Mashroom for Id
Karnala Bird sanctury
If lower surface shows gills then Pleurotus, if pores on the lower surface then Podoscypha
…. considering this mushroom to be Podoscypha petaloides suggested by my flickr friend, …
May be some Lentinus species as per representative images herein.
Looks different from images at Podoscypha petalodes (Berk.) Boidin
Maybe an old Pleurotus djamor, maybe.