Regarding Security Deposit - Under Lock-In Period

I have a Shop of 225 Sqft. with internal height of 12 feet so i made a mazennine floor with 6 feet height on top and bottom section. i myself use the upper (mazennine) floor for my personal use and rented out the other / lower section of the shop. The shop was rented to Party "X" (as i cant name the person) for 25000 Rent and 1 Lakh Deposit for 3 Years term with 1 Year Lock-In. Agreement was made in Mr. X name, running a firm named "CB". Within first 2 Months itself Mr. X shut the shop but his partners approached me that they will run the same business and appointed Mr. Y (another person from their side) to run the business in the same premise. Mr. Y somehow completed the lock-in period of 1 year and then he approached me for creating new agreement in his name with deposit of Rs. 1 Lakh (paid by Mr. X) to be carry forwarded in his name. Mr. X's partners approached me and requested the same to be done. i again entered into new agreement with Mr. Y with Rs. 27500 Rent and Rs. 1 Lakh deposit (which was paid by Mr. X) with 2 Years agreement and 1 Year Lock-In period. But again in 3 months (within Lock-In period) Mr. Y said he is not able to continue further and would like to terminate the agreement.He had not paid Rs. 35000 Electricity Bill and Rs. 6000 Water charges, which later i had to pay to the authorities. Now his Mr. Y's request is: 1) He want his balance deposit of Rs. 59000. 2) He is falsely claiming that i have not let him use the whole shop as i was using the mezannine floor. My point being: 1. I have already paid Rs. 41000 in terms of electricity and water charges used. 2. Its my fault that i had not specifically mentioned about the mezannine floor in the agreement. 3. i am entitled for atleast 2 months of rent which i can deduct from balance deposit. 4. According to me Rs. 41000 + Rs. 55000 (2 Months Rent) = Rs. 96000, so balance i can pay of Rs. 4000. i request for proper guidance as to what to do and can be done as Mr. Y wants no less than Rs. 59000. Thanking you.