JUDGMENT : B.N. Jha, J. 1. In this application under Articles 226 and 227 of the Constitution of India, the petitioner has prayed for the issue of an appropriate writ in the nature of certiorari and mandamus for quashing the ORDER :of the Collector dated the 17th May, 1965 (Annexure 'A') and that of the Commissioner dated the 13th November, 1965 (Annexure 'B') and directing the Collector to set aside the sale-deeds and the rehan-deeds dated the 27th February, 1961 and the 27th October, 1961, respectively and restore the land covered by the deeds to the petitioner. 2. The facts giving rise to this application may shortly be stated as follows: The land of Khata No. 62 of village Dumraon belonged to the petitioner. Plot Nos. 2285, 2286 and 2288 appertained to this Khata. The petitioner executed sale-deeds and rehan-deeds on the 27th February, 1961 and the 27th October, 1961, respectively in favour of Sheo Kumar Rai and another without obtaining permission of the Collector in respect of a portion of the lands of the aforesaid Khata as contemplated under Section 49-G of the Bihar Tenancy Act (hereinafter referred to as the Act). The petitioner because of his backwardness and lack of proper education and intellectual development was pursuaded to execute sale-deeds and rehan-deeds at a price which was much lower than the actual price of the land. He filed an application before the Collector of Shahabad at Arrah under Section 49-K of the Act for setting aside the aforesaid sale-deeds and the rehan-deeds in favour of the Opposite party 4 and 5 and for restoring the possession of the said land to him by ejecting the transferees. Opposite party 4 and 5 resisted the application on the plea that the petitioner Madan Bari was not a Bari, but was a Paneri and as such he was not a protected tenant within the meaning of Chapter VII-A of the Act. The Collector got an enquiry made by the Block Development Officer, Dumraon, in whose jurisdiction the village was situated. The officer made intensive enquiry into the matter and submitted his report with a finding that the petitioner Madan Bari was a Bari and was a protected tenant. The Collector was of the opinion that Section 49-K of the Act was not mandatory. The officer made intensive enquiry into the matter and submitted his report with a finding that the petitioner Madan Bari was a Bari and was a protected tenant. The Collector was of the opinion that Section 49-K of the Act was not mandatory. It gave discretion to the Collector to give relief to the transferor if he thought that the transaction was not a fair one. He was not satisfied that the alleged transaction was not a fair one. In his opinion, the petitioner Madan Bari was taking advantage of the provisions of the Act in a wrong manner. Moreover, he found that Madan Bari had subsequently on the 11th June, 1963, obtained permission to sell the land of Khata No. 62, plot Nos. 2285 and 2286 subject to his title and possession over the land. Hence, the petitioner's application was dismissed by the Collector on the 17th May, 1965 (Annexure 'A'). Against the said ORDER :of the Collector the petitioner filed an appeal before the Commissioner, Patna, who also affirmed the decision of the Collector, and dismissed the appeal by his JUDGMENT : and ORDER :dated the 13th November, 1965 (Annexure 'B'). Hence, the petitioner has filed this application in this Court for the reliefs stated above. 3. Mr. Jaleshwar Prasad, learned Counsel for the petitioner submitted that the view taken by the Collector and the Commissioner that Section 49-K is not mandatory, but gives discretion to the Collector to exercise his discretion in cases which he considers fit, is erroneous in law. He submitted that the petitioner is a protected tenant within the meaning of the Act and he can not transfer his land without obtaining permission of the Collector under Section 49-G of the Act. Hence, any transfer by a protected tenant in contravention of the provisions of the Act is invalid in law. On the other hand, Mr. Kailash Rai, learned Counsel for the respondents contended that the provisions of Sections 49-B, 49-C, 49-G and 49-K of the Act are discriminatory. The sole basis of the enactment is caste consideration and as such they are hit by Article 14(i) of the Constitution. Secondly he urged that the provision of Section 49-K is only directory and give a discretion to the Collector to exercise his discretion in suitable cases. The sole basis of the enactment is caste consideration and as such they are hit by Article 14(i) of the Constitution. Secondly he urged that the provision of Section 49-K is only directory and give a discretion to the Collector to exercise his discretion in suitable cases. The Collector has rightly refused to exercise his discretion in favour of the petitioner, in the circumstances of the case. Lastly, he submitted that this Court while exercising extraordinary jurisdiction should not interfere with the ORDER :s of the Collector and the Commissioner refusing to set aside the sales and mortgages when the petitioners have already received the benefits. 4. Chapter VII-A of the Act was inserted in the B.T. Act, 1935 when right to transfer his holding was given to an occupancy raiyat. According to the provisions of the Chapter, restrictions were imposed on the power of alienations of their land by aboriginals. The Chapter was originally applicable to the Santhals residing in the portions of the districts of Monghyr and Bhagalpur, which lay south of the Ganges, and for the purpose of this Chapter, the Santhals were deemed to be the aboriginals. The Provincial Government under Section 49-B was also empowered to extend the provisions of the Chapter in other parts of the province in relation to oilier class of persons. 5. Similar provisions existed in the Santhal Parganas. Section 29 of the Regulation III of 1873 imposed restrictions on the power of alienation of immovable properties by the aboriginals so that they might not fall in the grip of clever persons and might not be deprived of their lands. Section 20 of the Santhal Parganas Tenancy (supplementary provisions) Act, 1949 also contains similar provisions. Section 46 of the Chhota Nagpur Tenancy Act puts such restrictions on the power of alienation. Such provisions are intended to protect the interests of such weaker Section s of the society as are not capable of protecting their own interest on account of their educational and social backwardness. 6. The provisions of Chapter VII-A of the B. T. Act were extended from time to time in other parts of the districts of Monghyr, Bhagalpur, Purnea, Shahabad, and Champaran. 6. The provisions of Chapter VII-A of the B. T. Act were extended from time to time in other parts of the districts of Monghyr, Bhagalpur, Purnea, Shahabad, and Champaran. Ultimately in 1955 the heading of the Chapter was changed and in place of the aboriginals' as originally stood, 'protected tenants were substituted, and the Chapter was made applicable through out the State to the cases of protected tenants consisting of the members of the scheduled castes, scheduled tribes and backward classes. In the explanations given under Section 49-B of the Act scheduled castes and scheduled tribes are those classes of persons who are specified in part II of the Schedule to the Constitution. Section 49-B (3) provides that "Backward classes" means such classes of citizens as may be declared by the State Government by notification in the official Gazette, to be socially and educationally backward. The provisions of Chapter VII-A are intended for the benefit and protection of the three classes of persons who are notoriously, educationally and socially backward. The classification is based on intelligible differentia, which distinguish them from other classes of persons and are intended to give protection to such weaker class of persons. Therefore, the act could not be characterised as discriminatory and could not be held unconstitutional on that ground. Mr. Rai in view of the Full Bench decisions of this Court in Chaitram v. Sikandar Chaudhary M.A. 97 of 1962 decided on 16th Nov. 1967 has faintly contended that the notification issued by the State Government under Section 49-B of the Act declaring 'Bari' as a backward class is unconstitutional as it is hit by Article 14(i) of the Constitution. The notification runs as follows: The Government of Bihar was pleased to publish in Bihar Gazette dated 22-2-56, a list of classes of persons declaring them under Section 49-B of the B. T. Act to be socially and educationally backward. The notification in question is No. A/T 1015/55-1091 R dated 7-2-56, and has been published at page 572 of Part II of the said Gazette, The entries are the following: Classes of citizens Area 1. Bari Throughout the State. Mr. Kailash Rai submitted that the basis of the declaration of backward class is a caste consideration. It is difficult for me to accept this contention. Bari Throughout the State. Mr. Kailash Rai submitted that the basis of the declaration of backward class is a caste consideration. It is difficult for me to accept this contention. It is true that the persons belonging to Bari community are declared as backward but the sole basis of declaration of Bari as backward as mentioned in the Notification, is the social and educational backwardness of the community. In view of the decisions of the Full Bench, which has held the aforesaid notification constitutional and valid, it is not necessary for me to deal with this aspect of the contention made by Mr. Rai and the matter is concluded by it. There is a presumption of the constitutionality of the Act. Mr. Rai has not been able to place before us any material to show that the persons belonging to the Bari community are not educationally and socially backward. Article 15(4) makes it permissible for the State to make such legislation for the advancement of any socially and educational backward classes of citizens and for the scheduled castes and scheduled tribes. Therefore, the Act could not be said to be hit by Article 15(1) of the Constitution. In my JUDGMENT : the provisions relating to safeguarding the interest of the protected tenants are valid and the notification declaring Bari as a class belonging to a class of persons socially and economically backward is not unconstitutional. 7. Mr. Rai contended that the provisions of Section 49-K are not mandatory, but are directory and that they give discretion to the Collector to exercise the powers given to him under the Section in suitable cases where, in his opinion, justice requires to do so. Section 49-K runs as follows: Power to Collector to set aside improper transfer by tenure-holder, raiyat or under raiyat. If a transfer of a tenure holding or tenancy or any portion thereof, is made by a protected tenant in contravention of the provisions of Section 49-C, or it a transferee has continued or is in possession in contravention of the provisions of Sub-section (1) of Section 49-F or Section 49-G, as the case may be, the Collector, may, of his own-motion or on application made in that behalf after recording an ORDER :in writing, eject the transferee from such tenure-holding, tenancy or portion. 8. 8. According to his submissions the words, "the Collector may of his own motion or on the application made in that behalf, after recording an ORDER :in writing eject the transferee from such tenure-holding, tenancy or portion" merely show that Collector has full discretion in the matter. The provisions is only directory. The Legislature has clearly used the word 'may1 after the word 'Collector'. Had it the intention of the Legislature to make it mandatory, it would have used the word 'shall' which would have shown that the provision is mandatory. The argument advanced by learned Counsel for the respondents, does not appear to be sound. It is now well settled by the decisions of the Supreme Court that the word 'shall' in the statute is taken in the mandatory sense and does not necessarily mean that in every case it shall have that effect that is to say, that unless the words of the statute are punctiliously followed, the proceeding or the outcome of the proceeding would be invalid. On the other hand, it is not always correct to say that where the word 'may' has been used, the statute is only permissible or directory in the sense that noncompliance with those provisions will not render the proceeding invalid (see). The words have got to be construed with reference to their co-texts. Maxwell on the Interpretation of Statutes (10th Edition at page 243) while construing the word 'May' meant discretion to the Court has stated as follows: ...For these are cases where a power is deposited with public officers, to be used for the benefit of persons having rights in the matter. So, whenever a statute confers an authority to do a judicial act in a certain case, it is imperative on those so authorised to exercise the authority when the case arises and its exercise is duly applied for by a party interested and having a right to make the application, and the exercise depends, not on the discretion of the courts or judges, but upon proof of the particular case out of which the power arises. In the case of State of Uttar Pradesh v. Jogendra Singh (1963)IILLJ444SC it has been held that the word 'may' generally does not mean 'must' or 'shall. But it is well-settled that the word 'may' is capable of meaning 'must' or 'shall' in the light of the context. In the case of State of Uttar Pradesh v. Jogendra Singh (1963)IILLJ444SC it has been held that the word 'may' generally does not mean 'must' or 'shall. But it is well-settled that the word 'may' is capable of meaning 'must' or 'shall' in the light of the context. Where a discretion is conferred upon a public authority coupled with an obligation, the word 'may' which denotes discretion should be construed to mean a command. Some times, the Legislature uses the word 'may' out of deference to the high statute of the authority on whom the power and the obligation are intended to be conferred and imposed. The matter came for consideration before this Court in Sone Lal Jha v. The State of Bihar 1966 B.L.J.R. 8 137 in connection with the provisions of Section 3 of Koshi Area (Restoration of Lands to Raiyats Act) (Bihar Act 30 of 1951). Section 3 of that Act are in the following words: ...the Collector may, if he thinks fit, of his own motion, or otherwise, take steps for the restoration of such holding or portion thereof to the said raiyat. This Court held that the word 'may' should be construed to mean a command and the provisions are mandatory. 9. In the present case Section 49-C of the Act provides that no transfer by a protected tenant of his right in his tenure, holding or tenancy, or in any portion thereof, by private sale, gift, will, mortgage, lease or any contract or agreement, shall be valid to any extent except as provided in this Chapter. Section 49-J provides that "no transfer by a protected tenant in contravention of the provisions of this Chapter shall be registered or in any way recognized as valid by any Court, whether in the exercise of civil, criminal or revenue jurisdiction." Section 49-G provides that if a protected tenant wanted to transfer his land, or any portion thereof, by private sale, gift or will to any person, he had to apply before the Collector for permission to make the transfer. The transfer if permitted by the Collector would be effected by a registered document after obtaining written consent of the Collector to the terms of the deed and to the transfer. The above provisions clearly show that a protected tenant has got no free hand to deal with his lands in any manner he liked. The transfer if permitted by the Collector would be effected by a registered document after obtaining written consent of the Collector to the terms of the deed and to the transfer. The above provisions clearly show that a protected tenant has got no free hand to deal with his lands in any manner he liked. If the conditions and restrictions, as laid down under Section 49-C and 49-G are not observed by the transferor and the transferee, the transferee is presumed to have taken advantage of the social and economic backwardness of the protected tenant and the Collector is empowered to impose penalty on such a transferee by putting the transferor in his original position, as if there had been no transfer at all Section 49-K as quoted above, clearly shows that the duty is cast on the Collector to take steps for the restoration of the land to the transferor or to the heirs of such transferor, if the transferor is dead and if the transfer has taken place in contravention of the provisions of this Act. In the light of this context, it is manifestly clear that the word 'may' (in Section 49-K connotes command on the Collector to use his powers in cases where conditions for restoration of the land from the transferee to the transferor exist). In my opinion, there is no force in the contention of Mr. Rai that Section 49-K gives discretion to the Collector to exercise his discretion in the cases he considers just and proper. 10. Lastly Mr. Rai submitted that this Court should not exercise its discretion in the circumstances of the case as the petitioner after executing the document received the consideration money and put the transferee in possession of the lands. In his submission, the petitioner is estopped from challenging the transaction after having; received benefits under the transaction. It is well settled that there is no estoppel against statute. Equitable estoppel has absolutely no application to cases where there are clear provisions of statutes. In his submission, the petitioner is estopped from challenging the transaction after having; received benefits under the transaction. It is well settled that there is no estoppel against statute. Equitable estoppel has absolutely no application to cases where there are clear provisions of statutes. In that connection the famous observation made by Lord Russell in Ariff's case 58 I.A. 91may suitably be quoted which runs as follows: - Their Lordships do not understand the dicta to mean that equity will hold people bound as if a contract was in fact made;; nor do they understand them to mean that equity can override the provisions of statute and (where no registered document exists and no registerable document can be procured) confer upon a person a right which the statute enacts shall be conferred only by a registered instrument. Even if any such equity was established, their Lordships are of opinion that it could not operate to nullify the provisions of the Indian Code relating to property and transfers of property. The transferees entered into transaction with open eyes subject to the limitations imposed by the provisions of the D.T. Act, and took the transfer with all its consequences. In such circumstances, there is nothing in this case for the High Court not to exercise discretion in favour of the petitioners. I am not prepared to accede to the submissions made by Mr. Rai. 11. In the circumstances stated above, the ORDER :s passed by the Collector and the Commissioner (Annexures A and B) are erroneous in law and must be quashed. The case is remitted back to the Collector for deciding the case according to law. The petitioner is entitled to costs; hearing fee Rs. 100/-. R.L. Narasimham, C.J. 12. I agree.