I just searched for phonetic of понял and found these:
Please let me know that both are correct? and have same meaning as Got it!?
по́нял [пон’ил] is the only correct form use for either questioning and confirmation.
поня́л [пан’ал] is an informal form commonly used to question (the closest would be "do you get it?"). It's not so much of a mockery but pretty patronizing way which you wouldn't use with people you don't closely know as it has a condescending sounding to it.