Is it allowed to put shed of translucent fiber sheet for safety, privacy & hygiene?

I have a flat under PMRDA in a co-operative housing society. My flat is at 4th floor. I have a side terrace attached to my flat. This side terrace is open to sky. Windows of all the flats above my flat open in my side terrace. There are many incidents where different items are being thrown from these windows into my terrace. It is very difficult to catch the actual person as there are many flats above my flat. Also there is lot of Pigeon droppings. I am worried about the safety of my family, privacy & hygiene. I want to put shed of translucent fiber sheet on this terrace for the safety, privacy & hygiene. I contacted society members, explained my problem. They understood my problem, but told me that they do not have rights to provide the permission. They asked me to get permission from PMRDA. Is it allowed to put shed of translucent fiber sheet for safety, privacy & hygiene? What is permissible and what is not permissible on a side terrace? What is the procedure to get permission from PMRDA?