Property Owner refusing to register the property after Sale Agreement

Hi All, I have planned to buy an apartment and placed a sale agreement with the owner by giving 10% of the total value for two months. I had applied loan and my loan got sanctioned. After that it is almost 5th time we have put token in the register office, invited them for registration and waiting. Exactly one or two hours before the token time, owners are telling some junk reasons and skipping the registration. At one point, we had some bad discussion and the owner signed the Sale deed as well just to give me some hope that he will come for registration. But even after that he is not coming for registration. I am ready with sale deed as well with both parties signed. What should I be doing? If I approach legally, I know I need to send a letter to the owner saying that I am ready for registration kind of. After that I am planning to place a CSR in my village police station just to have an initial enquiry and see what they say. If I go to court for registration, how long does it take to finish the case?