Buying mortgaged property

A MOU was signed by seller & Purchaser for a mortgaged property. As per MOU Purchaser had to pay 90 Pct of property value to mortgaged bank and 10 Pct into Seller's individual account after clearance of loan.. The seller with cheating & dishonest intentions orally convinced and motivated Purchaser to transfer entire 90 Pct bank loan amount into his individual account. He convinced purchaser that he will get discount from Bank if funds are transferred into his account.He will pay to bank after discount negotiations. Seller did not pay bank loan .Seller executed partial sale agreement and stated that he will clear bank loan soon and will execute the final sale deed. As per sale agreement loan to be cleared within 40 days of sale agreement . Thereafter after balance payment by purchaser sale deed to be executed. Seller did not clear bank loan after 40 days of sale agreement and has not cleared home loan since last 6 months . He is giving false promises again & again that he will clear loan and will execute the sale deed but not doing so. Purchaser is in deep trouble by transferring funds into seller's account instead of mortgaged bank account. Seller's intentions are not to pay loan and execute the deed. Please advise how purchaser should proceed to force seller legally for repayment of loan and executing of sale deed of property. Should Purchaser proceed to nearest police station and lodge a complaint for cheating under IPC code 420 or he should approach court and serve notice for the breach of sale agreement. Seller did not pay a single penny to mortgaged bank and