Property dispute

I have a property in a place A which I leased to someone who was using it to sell liquor. I and he made an agreement in which he would provide the money to build to another floor of the building and whatever amount was invested by him, I will not pay him back instead he would not give me the rent. After a few years, he proposed to buy the property for 30 lakhs. Since the liquor was banned he decided to cancel the deal. In between, I had taken 2 lakhs in cash (add other 7 lakhs invested in construction)from him as a token amount while the deal was still on. In 2018, he again proposed to buy the property. But I increased the price from 30 lakhs to 40 lakhs because someone else had proposed to buy my property for 40 lakhs. He is not willing to buy it for 40 lakhs and is asking me to return all the money he invested which amounts to 9 lakhs. I am willing to pay him back but at the same time, he does not want to pay the rent of 4-5 years after the cancellation of the first deal. He wants to now re-negotiate the deal for 34 lacs instead of 38 lacs (40-2 lakhs) and if I do not sell him property I should pay him back the money with interest(there is no question of interest since I had taken only 2 lakhs in cash and that too as token amount and there was different agreement for the investment made in the construction) since I am asking him to pay the rent of property because he used the property even after cancellation of the first deal. I wanted to know whether I am at any fault legally?