Evicting a tenant

Hello: Kind request experts to advise on the below issue. My tenant has been staying on my property for around 30 years. He has constructed the building on his own in my premises with his money. The understanding was that I, the landlord, have to repay the money back within a specified period of time. If the money is not repaid back, then he (the tenant) gets to stay on my property for an extended period of time. Although the money was repaid in complete, it was not within the specified time frame. As such, as per the agreement, which is not a registered one, my tenant gets to stay for an extended period of time as mentioned in the agreement. I tried to get my tenant evicted legally, but the judgment was passed in favor of my tenant citing the reasons mentioned in the agreement as mentioned above. Now, the tenant is staying on my property for an extended period of time for a paltry sum of money as rent. Neither I am able to get him evicted legally, nor am I able to dispose of the property as he is stuck there till the lease period ends. Kindly request experts to advise on this. I would like to know if there is any way of getting my tenant evicted.