Can a black hole collapse in itself? As we know that the black hole is a lump of highly dense matter, and that's the reason for it's so strong gravitational force. Bat let us assume that it has sucked up a huge amount of mass and it's gravitational force has become of very high strength. Than what will happen. Will the black hole collapse in itself like a dying sun an give birth to another worst nightmare for the cosmologist or anything else will happen.
 A: According to general relativity, the matter in a black hole is already collapsed down to a volume of exactly zero.  It is not meaningful to talk about further collapse.
A: A black-hole is the most dense, most collapsed object or state of matter in the universe.  To our knowledge, nothing really changes as a black-hole increases in mass except that it gets bigger, and its gravity stronger.  Its properties are, for most intents and purposes, scale invariant1. 

1: Hawking Radiation is, in a way, an exception to this, but not astrophysically relevant.
A: The collapsing of the black hole is impossible. It is like trying to burn ashes. Ashes are already burnt. Similarly, the black hole is already collapsed. The black hole can evaporate and get bigger, but not collapse.
A: Black holes can evaporate. Black holes formed beneath the Chandrasekhar limit will evaporate quickly.
A: Well a black hole actually has 5 tons of mass or in other words a stellar hole if it collapsed into itself it would cause a hypernova
Because according to the law of consevation of mass that mass cannot be created or destroyed but it can be rearranged in space therefor no mass can be .000000000000000000
Because that would mean a mass has been removed but most black holes have more than 10 times the mass of the sun my source is http://amazing-space.stsci.edu/resources/explorations/blackholes/lesson/whatisit/stellar.html
