durablity and brand? Here's some photos:on the left is the suspension,on the right is the crank set,on the bottom left is the front derailleur and on the bottom right is the back derailleur  

I recently spray painted my bike that was given to me by someone, and then, I suddenly got curious to find what is the brand of this bike but i couldn't as it was covered, so any idea what brand it might be?  

Also, will it be suitable to ride on rough terrains using it? or parts to upgrade it?

EDIT: After a month of research, I think this is an EVEREST brand mountain bike.is it any good?   And it is steel?
You'd probably get a good information by looking at the components.  Assuming the components are original, you can tell a lot information about the general quality of the frame from the quality components. Almost nobody is putting DuraAce on a cheap Walmart frame, and almost nobody is putting Tourney parts on a Cervello.  The bolt on wheels and ProMax crank lead to me believe that this bike is more likely from Walmart or another department store. That doesn't mean it is, but it could be.  Also, it has V-Brakes, which most quality full suspension bikes don't use any more. They've almost entirely switched over to disk brakes at the high end.  Get some more pictures showing close ups of the derailleurs, crankset, suspension, and the markings on the rim of the wheel to help us evaluate it further.