I feel Kavin will be the title winner.
In season 1 total 14 weeks and aarav became captain only in week 12.
In season 2 total 15 weeks. week 14 and 15 no captain and Rithvika became captain only in week 13.
Also both aarav and rithvika was not part of captaincy contender for many weeks.
If same logic applied then high chances for kavin to win the title.