You start searching new buyer and who will pay more money than her on immediate basis atleast  50% of amount of new amount and return his 44% amount of old transaction. Once the limitation date is crossed.

After 10th Jan you are free search new buyer and make new transaction and cancel old transaction.

Meanwhile you can send him a legal notice or just notice in legal format from your email id to on his or her email id to complete the transaction or else the transaction will bought to get terminate or cancel on 10 Jan 2020.

Keep this in writing don't say anything in oral or verbally to her.

Issue notice to buyer to pay balance amount so that you can register sale deed in favour of buyer 

2) if he fails to make balance payment within period mentioned in agreement you can cancel the agreement and refund money received by you  or file suit for specific performance 

Dear Sir,

you have a very strong case. Just cancel his agreement and forfeit the entire advance amount paid. Let him go to the Civil Court. You are in safer zone.

1. In this scenario you may serve a lawyer's notice for cancellation of agreement to sell to the buyer for default in conditions spelled out in the agreement.

2. The amount paid so far has to be returned by you to him minus the forfeiture charges, if any, mentioned in the agreement.

3. You can send a reminder letter also before sending legal notice.

Hi

You can issue notice to him demanding balance sale consideration and to get the sale deed executed as per terms of agreement.

If he fails to honour your demand, forfeit / return the advance received by you, as per terms of agreement.

If he fails, then you can file suit for specific performance

You can file a suit under specific relief act and seek interim relief of registration and balance payment for the same

You can send a reminder at this stage for due payment and the registration if on that also he try to drag for registration after agreement date send him a legal notice for cancellation of the agreement. 

Since you are the absolute owner of the plot, and the buyer is dodging payments, wait upto [deleted], if the buyer does not come forth by paying the balance sale consideration and completing the registration process, simply proceed to issue a legal notice of cancellation of sale agreement post [deleted] and forfeit the entire amount paid by the buyer.

After doing this, go ahead and resell the plot to a different buyer.

Don`t accept further payment and issue notice of termination of agreement for failure to make pyment in given time. Since agreement is not registered and executed of lower stamp paper, hence cannot be enforced through court.

Asyou told there is a agreement Between you and buyer. Without going through the clause of the agreement, it is difficult to give solution to the question.

1. You cannot send any legal notice to buyer before completion of agreement period but you can send a reminder letter with registered post to buyer that agreement is going to be expired on so and so date and registration should be done on or before that date or agreement will stand cancelled.

2. After expiry of agreement period you can send legal notice for cancellation of agreement due to non payment of dues and offer to refund the money without interest after nominal deduction for loss of opportunities.

You may issue a notice t the buyer immediately mentioning the details of the agreement and and express your willingness and readiness to execute the registered sale deed in his favor upon he paying the balance of  sale consideration amount on or before the stipulated date as mentioned in the ale agreement on a date fixed up by him as per convenience.

You can also mention that as per the agreement of sale if the buyer fails to turn up for registration of sale deed by paying the remaining sale consideration amount the advance amount paid shall be forfeited to the extent of the administrative costs and the balance would be returned to him after the cancellation of the sale agreement and that the buyer would be held liable for the costs and the legal consequences.

If you do not know the procedures or the legal terminologies to issue this legal notice, you may contact any advocate in the local and cause to issue this legal notice.

First, please send the intended purchaser a legal notice asking him to pay the balance on or before a set deadline and asserting that if if he fails to do so, you will forfeit the amount he has paid so far and proceed to sell the property to anyone else without further notice.