JUDGMENT Ram Surat Ram (Maurya),J. Heard Sri Govind Saran Nigam for the petitioners. 2. This writ petition has been filed against the order of Judge, Small Cause Court dated 10.12.2013, rejecting the amendment application of the petitioners, for amending written statement. 3. Anuj Agrawal (respondent-2) filed an application (registered as RCPA No. 7/2012) under Section 21(1)(a) of U.P. Act No. 13 of 1972 for release of the shop in dispute, which is in possession of the petitioners as a tenant. The case was contested by the petitioners and they filed their written statement on 05.03.2013. After filing of the written statement, the petitioners filed an amendment application under Rule 34 of the Rules framed under U.P. Act No. 13 of 1972 on 12.11.2013 for amending the written statement. The proposed amendments are in effect for adding paragraph 14-A in the written statement, raising the plea that respondent-2 purchased the house in dispute through sale deed dated 07.01.2006 and filed a release application on its basis, without giving six months previous notice, as required under Section 21(1)(a) proviso of the Act as such release application was not maintainable. The aforesaid application has been heard by Judge, Small Cause Court, who by the impugned order dated 10.12.2013, found that as trial had already commenced, as such, in view of proviso to Order 6 Rule 17 CPC, the amendment could not be allowed. On this ground amendment application was rejected. Hence, this writ petition has been filed. 4. The counsel for the petitioners submits that proviso of Section 21(1)(a) of U.P. Act No. 13 of 1972 raises a legal issue relating to maintainability of the release application. The provision has been held to be mandatory by the Supreme Court in Nirbhai Kumar v. Maya Devi, (2009) 5 SCC 399 . The plea sought to be raised by way of amendment, being the legal plea, was necessary for deciding the real controversy between the parties, the amendment ought to have been allowed by Judge, Small Cause Court, exercising its power under second part of Order 6 Rule 17 CPC, but it has been illegally rejected. 5. I have considered the arguments of counsel for the petitioners and examined the record. 6. 5. I have considered the arguments of counsel for the petitioners and examined the record. 6. Supreme Court in Nirbhai Kumar's case (supra) held that although Proviso to Section 21 (1) (a) of U.P. Act No. 13 of 1972, which contemplates of six months' previous notice, is mandatory for initiation of proceeding under Section 21(1) (a) of the Act, but the tenant has right to waive it. The petitioners filed his written statement and has not raised the plea regarding six months' previous notice. Thus the petitioners waived their right as contemplated under the proviso to Section 21(1) (a). Proposed amendment amounts to withdrawal of the waiver of the petitioner which cannot be permitted to be withdrawn by way of amendment. Supreme Court in Modi Spinning & Weaving Mills Co. Ltd. Vs. Ladha Ram & Company, (1976) 4 SCC 320 , Heera lal Vs. Kalyan Mal, (1998) 1 SCC 278 , Gautam Swaroop Vs. Leela Jetly, (2008) 7 SCC 85 , Sumesh Singh Vs. Phoolan Devi, (2009) 12 SCC 689 and Vishwanath Agrawal Vs. Savitri Bera (2009) 15 SCC 693 held that an admission cannot be permitted to be withdrawn by amendment. Same principle will apply in this case also. 7. The counsel for the petitioners submits that the earlier counsel engaged by the petitioners has expired. Thereafter, they engaged a subsequent counsel, who noticed the defect in the written statement. The petitioners, being a semi illiterate persons, had no knowledge about the law, in such circumstances, the proviso to Order VI Rule 17 C.P.C., which requires 'due diligence' should not be invoked. 8. Order VI Rule 17 C.P.C., as amended in the year 2002, is quoted below: - "17. Amendment of pleadings.--The Court may at any stage of the proceedings allow either party to alter or amend his pleading in such manner and on such terms as may be just, and all such amendments shall be made as may be necessary for the purpose of determining the real questions in controversy between the parties: Provided that no application for amendment shall be allowed after the trial has commenced, unless the Court comes to the conclusion that in spite of due diligence, the party could not have raised the matter before the commencement of trial." Supreme Court in Salem Advocate Bar Assn. (II) v. Union of India, (2005) 6 SCC 344 , held that Order 6 Rule 17 of the Code deals with amendment of pleadings. By Amendment Act 46 of 1999, this provision was deleted. It has again been restored by Amendment Act 22 of 2002 but with an added proviso to prevent application for amendment being allowed after the trial has commenced, unless the court comes to the conclusion that in spite of due diligence, the party could not have raised the matter before the commencement of trial. The proviso, to some extent, curtails absolute discretion to allow amendment at any stage. Now, if application is filed after commencement of trial, it has to be shown that in spite of due diligence, such amendment could not have been sought earlier. The object is to prevent frivolous applications which are filed to delay the trial. There is no illegality in the provision. 9. The phrase "due diligence" came for consideration before Supreme Court in Chander Kanta Bansal v. Rajinder Singh Anand, AIR 2008 SC 2234 , in which it has been held that the words "due diligence" have not been defined in the Code. According to Oxford Dictionary (Edn. 2006), the word "diligence" means careful and persistent application or effort. "Diligent" means careful and steady in application to one's work and duties, showing care and effort. As per Black's Law Dictionary (18th Edn.), "diligence" means a continual effort to accomplish something, care; caution; the attention and care required from a person in a given situation. "Due diligence" means the diligence reasonably expected from, and ordinarily exercised by a person who seeks to satisfy a legal requirement or to discharge an obligation. According to Words and Phrases by Drain-Dyspnea (Permanent Edn. 13-A) "due diligence", in law, means doing everything reasonable, not everything possible. "Due diligence" means reasonable diligence; it means such diligence as a prudent man would exercise in the conduct of his own affairs. 10. Supreme Court again in J. Samuel v. Gattu Mahesh, (2012) 2 SCC 300 , held that due diligence is the idea that reasonable investigation is necessary before certain kinds of relief are requested. Duly diligent efforts are a requirement for a party seeking to use the adjudicatory mechanism to attain an anticipated relief. An advocate representing someone must engage in due diligence to determine that the representations made are factually accurate and sufficient. Duly diligent efforts are a requirement for a party seeking to use the adjudicatory mechanism to attain an anticipated relief. An advocate representing someone must engage in due diligence to determine that the representations made are factually accurate and sufficient. The term "due diligence" is specifically used in the Code so as to provide a test for determining whether to exercise the discretion in situations of requested amendment after the commencement of trial. A party requesting a relief stemming out of a claim is required to exercise due diligence and it is a requirement which cannot be dispensed with. The term "due diligence" determines the scope of a party's constructive knowledge, claim and is very critical to the outcome of the suit. In the given facts, there is a clear lack of "due diligence" and the mistake committed certainly does not come within the preview of a typographical error. 11. The written statement was drafted by an advocate after reading the original application and reply of the facts as well as plea for contest on behalf of the petitioners were raised in it. After legal advice, it cannot be said that in exercise of due diligence the fact sought to be brought in the pleading by way of amendment was not in the knowledge of the defendants. A distinction has to be drawn between 'due diligence' and 'negligence'. The case of the petitioners falls in the category of 'negligence' and not 'due diligence'. Trial Court has not committed any illegality in rejecting the amendment application. 12. In view of the aforesaid discussions, there is no illegality in the impugned order. The writ petition has no merit and is dismissed.