Is there a place in the universe where time doesn't exist?
and question:
Don't know if it's valid though. What could be a strong proof for the same?
Please note that "proof" applies to mathematical formulae, not to physics. Physics confirms or falsifies a statement predicted by a mathematical formula. To confirm , one has to measure and measurement includes change and when there are changes time can be defined.
The comment by CuriousOne is correct. Singularities exist only in the mathematics and are a signal for the failure of the model at the singularity.
For example take electron positron attraction in classical electrodynamics. There is a singularity at r=0 . This is eliminated by the quantum mechanical solutions, which allow for stable quantized states . And if the electron and positron fall on each other no infinity appears, but a decay into two photons.
It has a mean lifetime of 125 picoseconds and decays preferentially into two gamma rays with energy of 511 keV each (in the center-of-mass frame). Detection of these photons allows to reconstruct the vertex of the decay and is used in the positron-emission tomography.
This clearly shows the limits of classical modeling with the infinities and the new physics modeling with quantum mechanics.
In a similar way, all measurements confirm special relativity, and its mathematical formulation says that no massive particle can move with the speed of light because there is not enough energy in the universe to reach that velocity.