Pent House illegal construction - Hyderabad

Dear Madam/Sir, In the year 1993 builder constructed an apartment which has 6 floors permission was sought for 5 floors. A part of Sixth floor is common terrace and in another part a (pent house) was constructed without necessary permission from municipality. The pent house is around 1500 sq ft of which approx 500 sq ft is open terrace. A person can access this terrace only via the pent house and no other common entry point exits. The flat was sold to Mr. A by the builder & the landlords in 1993. in 1998 Mr. A applied for regularisation of the said flat by paying the application fee, However it is not yet regularised and file is still pending. we were occupying this flat as tenant from 2006. In 2017 we purchased the flat. To make the terrace more productive we constructed shelves by laying tandoor stone which were supported by bricks and cement. The resident below our flat start objecting to it and informed as that the terrace is common property and we cannot carry out any construction activity on it. To which we stopped, however he also made a complaint to GHMC. Now we have received a notice from GHMC u/s 452(1) and 461(1) of GHMC act 1955. Which states that you have made the following deviation/unauthorised construction Details of deviation/unauthorised construction: a)unauthorised construction Pent House b) Encroachment of terrace area. Please let me know what can I do know. 1. Does construction of shelves require specific permission from GHMC or the building association. 2. Does the terrace belong to us? we have exclusive access right and also no objection was made by any of the occupants till the date of construction.