I. Facts in brief - Basis of plaintiffs claim:

Plaintiff in the suit for specific performance is the appellant. The owner of the property, who is the brother of the plaintiff, is arrayed as the 1st defendant. Defendants 2 to 4 are the sons of the 1st defendant. The 5th defendant is the subsequent purchaser. The suit is filed on an agreement of sale alleged to have been executed by the 1st defendant in favour of the plaintiff under Ex.A-1 dated 19.03.1983. The terms of the agreement spell out that the consideration had been fixed as Rs.47,000/-and on the date of the agreement, an advance of Rs.5,100/-was paid and the balance of sale consideration was to be paid within a period of two months. According to the plaintiff, after the execution of the agreement, he learnt that there had been a mortgage, which was still outstanding with Shantha Devi and he paid Rs.20,000/-on 12.05.1983 and obtained a receipt under Ex.A-2. Yet another encumbrance was to a person, by name, Mythili and a portion of the debt was discharged by him by payment of Rs.9,790/-. Corporation tax had not been paid and arrears to the tune of Rs.4,947.19 was paid by the plaintiff to the account of the 1st def