Withdrawal of mutual consent

The answer is possible no. They are trying extort money. If you have the decree of divorce and the copy of MOU. Please lodge a police complaint and send a legal notice to them through your lawyer that you would take necessary legal action and proceed criminal proceedings if the calls are not going to stop. 

Disclaimer: I am not the Lawyer.

Mr. Sagar, you have to clarify two things. (1) You said that a decree of divorce has been passed ,after a mutual consent that too payment of Rs.10 Lakhs. Have you and your wife entered into a compromise memo into court, with all facts. What both of you, mentioned the grounds for taking divorce.  (2) What document you have filed before the Family Court and what grounds both of you entered , These information should be helped you in solving the problem of demanding further amount of Rs.5 Lakhs by your wife. 

Dear Mr. Bala.

the clarifications are as below.

1 - me & my wife have given joint petition in the Family court saying that due to irreparable differences between us, we are staying apart for the past 6 years, further we have arrived to a decision that full & final settlement for maintenance of 10 lakhs to be paid to her & in turn she will give-up her all rights for the claim. After this we were sent to the conciliation & mediation judge, the Family court gave 6 months of time. After this time period we were again called for re-conciliation & then we gave separate affidavits at one time in the Family court, saying that we want to go for divorce as the re-conciliation has failed. For this court accepted the affidavits & passed an order for divorce under mutual consent.

2- regarding documents, I have paid her the amount through DD & photocopy attached, in the receipt she has written & said that full amount has been received & shall not have any further claim on me.