Property owner is not signing agreement after receiving payment

Hello, My parents saw a property and finalized it. We now the owner from over 10 years. He stays in our locality. It was decided that I will pay 40% now and the rest after 6 month. Agreement was prepared, but before he would sign he asked us to transfer money into his account. I was in different city at that time. Since there is a limit to transfer in a day, I could only transfer 5 lakh rupees a day. I transferred it over 4 days. And when my parents went to get the agreement signed. He asked to allow him a couple of more days days for him to decide how much time he can exactly give us to pay remaining amount as can't wait for 6 months as he has some other obligations. My parents went after 2 days then he asked to give him 4 more days. This has been going on from last 20 days. We are not sure about his intention at this point. What legal action can we take? Thanks in advance for your help!!