Buyer not ready to fullfil the sale agreement. Unilaterally cancelling giving personal reason.

Hi Sir/Madam I am facing problem with buyer. I am ABC the PUCHASER of the below site. And XYZ is the SELLER of the site. Property, 30X40 feet. Total 1200 sq ft. which is a Non-Agricultural site (NA Site) agreement happened between ABC and XYZ is total value of 18 Lakhs. Agreement happened on 04.07.2024 by paying on account 3.5 Lakhs to seller account through cheque transfer. On 28.07.2024 seller requested for more money on emergency so provided cash of 2.5 Lakhs so total paid 6 Lakhs out of 18 Lakhs. Both the party planned for registration on 05.09.2024, (Content drafter registration/stamp duty fee not paid) before one day i called and shared information what are the documents should be transfer to me by buyer. On the same call Buyer said, he is not ready to come and register the property because his father is against the sale of property. I have following documents: 1. Valid sale agreement with terms and conditions and clearly mentioned "Cancellation of agreement can be done only on mutual understanding and any unilateral decision by one party then other party can claim damage and compensate" and another extension of agreement where 2.5 lakh paid in cash. 2. Buyer details, All property documents, EC, Form 9/11 etc., 3. Buyer bank account 4. Transfer cheque and credited details including my own bank statement saying that i have balance amount in my account to purchase the property on that day. But buyer not ready to complete the process. 5. I have all call recordings of SELLER and PURCHASER talked specific to matter. (No privacy violation) 6. I have witness in favour of my side. (Still 2 witnesses are BUYER friends, they still ready to give statement as is) Now my queries : 1. I want to purchase the above property not ready to accept the compensation or advance amount refund with interest by buyer. Because I am planning to construct house in that site (Area) and shift my family. I got that site for best price. If i can't get property, how much compensation or damage i can ask from the buyer through court. or Court may decree saying Buyer to fulfil as per the agreement ? 2. Can i keep call recordings as evidence ? buyer clearly stated saying that i am unilaterally cancelling the agreement and not ready to complete the respiration process. Indian Evidence Act i am ready to give affidavit on the same that recordings not edited or modified anything. In such cases i am responsible. 3. Buyer ready to refund my amount with interest i don't want this, i need property only. can i fight with agreement ? to get property. 4. Buyer cancelling because of personal reason saying " His father is against this sale agreement so he is not ready to proceed further) will this stand in court ? 5. How many year may take this case ? approx. what are the possibility of court order. Please provide answers to my specific question point by point it will help me. I am consult also.