Window Safety Box Grill Legal In Navi Mumbai

I live in Ulwe, Navi Mumbai where CIDCO is an administrative authority. I have installed a window safety box grill in my balcony. This grill is extended 18' outside my Window balcony, now society is questioning me about my window grill. Is it legal to have safe grills installed on the balcony? If yes what is a maximum extension is allowed?