Registry even after last date has elapsed and 3 yrs have passed since then

WE have a house in my mother’s name but for last 25 yrs, her brother and his son were occupying it. We always wanted to sell it but the brother's son Mr X, was creating problems in selling it. In Dec 2013 , my mother entered into a agreement with a buyer: 1. Buyer to do registry by 29th mar 2014, failing which the token money will be forfeited 2. Mr X is currently staying in the said house. Buyer to get the consent of Mr X and formalise a consent document. My mother will have no objection to the terms and conditions of this consent letter 3. After 29th mar 2014 , this agreement will be null and void 4. Mr X also signed as witness to this agreement Following this buyer paid us a token of 6 Lacs and also got the property diverted for bank loan. But the buyer could not get the house vacated from Mr X by March 2014. Lot of to and fro reminders and letters happened during that time. Then in April 2014, Mr X , gave possession and keys to buyer. Now buyer has filed a court case to do registry stating that he got possession in april 2018 and hence registry shd be done at old rate. My mother broke his locks and took possession of the property. The case is before the district sessions court and no stay has been put till now .My query is: 1. Can this case be not allowed to progress as 4.5 yrs have passed since 29th march 2014? As per my understanding, 3 yrs is the time period during which token related real estate disputes can be filed in the court. 4.5 yrs have elapsed 2. He has paid only 1.6 Lacs as the court fees, whereas the agreement value was 35 lacs. Isn’t the court fee less 3. Possession of a property is given after the registry. Buyer has not got the registry done till now, so how can he claim possession. Moreover there was special provision of last date by which the agreement was signed. He had to take possession / get Mr X to vacate the house as per the consent letter clause in the agreement. To this clause he has agreed and signed, so my mother was not involved with giving possession of the property. He himself says in his court petition that as per the agreement, he had to get Mr X to vacate the house. To this date, he has not signed any consent letter with Mr X. It was/ is all verbal between the two of them, to which my mother has no role to play. What are our chances of winning the case 4. Can my mother file a case on Mr X to vacate the property? In 2010, Mr X father sent a letter to her, with all falsehood that my mother had verbally agreed to give him the money after selling the property. And that Mr. X father has invested in the said property from the start. Mr X father is my mother’s real brother and has signed as witness in the original registry, when my mother was purchasing the property. My mother replied that this is all falsehood and if her brother had invested in the said house , then his name would have been as a co-buyer in the original registry, rather than a mere witness .