Land agreement

The party informed you very late i.e. more than 2 yrs of your land agreement.  The intention is malish, you may verify and go ahead.

Time is  not essence of contract and the period of limitation is three years from the date of agreement, see if the party has sent you the notice within three years period, or check up if your agreement has any specific recital stating that the performance of either party is to be completed within the time stipulated therein, then that applies, that way the other party loses his claim automatically quoting the time is essence of contract.  Contact a prudent local lawyer with the document and seek his advice for further proceedings.

In specific performance of contract both the parties to contract have to perform their part as per agreement ..In case any one of party fails to perform his part other party has right to get performed the contract through court.It has to  seen whether you were ready to perform your part or not ?Whether you were ready to pay balance amount to other party or not ?Generally time is not essence of contract and in your case it seems that you had not made any objection after expiry of time period so time is not essence of contract in your case.issue a legal notice to opposite party immediately and ask him to perform the contract .If he fails to perform then file suit for specific performance against him.