Is 10 years of rental agreement safe and valid in Andhra Pradesh,

Hello There, I have a property rented out in Vishakapatnam, Andhra Pradesh from past 15 years being renewed the rental agreement in every 5 years. In the upcoming month the latest rental agreement is being expired and we are due for making a new one. But this time the party is insisting to make it for 10 years because they want to invest huge money in terms of infrastructure enhancement and they can’t take that decision if it is not for minimum 10 years. I am worried to make it for 10 years, as had already been rented out to them from past 15 years and is being asked for another 10 years. In the past 15 years, there were no instances of any glitches between us nor created any problem in giving the timely rent. They have always been sincere and professional in nature. I have below 2 questions, 1. Is 10 years of rental agreement valid in Andhra Pradesh, India? Rental agreement for 10 long years is not valid in few states according to my knowledge. 2. Is it safe to rent out to the same party for another 10 years (who have already been there for past 15 years) which put together makes 25 years? Does not it fetch them any rights on the property according to Indian court of law? I would extremely appreciate for any clarifications in this regard. Sincere Thanks Sri Harsha