1.after the expiry of the written agreement ( not stamped and registered can the first party force me to sell to him only?
Answer: After the expiry of 45 days, you are not legally bound to sell it to the original buyer;
2. Since the agreement is not signed by the co owner is it valid, ( since my sister is in Bangalore she has given me oral consent to sign agreement)
Answer: If the co-owner has not signed it then irrespective of the 45 days time period, the agreement is not valid;
3.I came to know through the second buyer that he has to buy the same plot from him at an inflated rate which is around 10 lakhs. now with all this tension I do not want to sell the plot So, how do I go about it?
Answer: You can back out from the sale to the second buyer if there was agreement to purchase at a fixed value and no other terms and conditions;