Hello, Greetings of the day!
For the query you posted, I would suggest that:
If either of you changes religion then there will not be any impact on your marriage and it may continue with subject to your own understanding, change of religion by one spouse is not change for the other one as it may continue to remain in the same religion.
But if your partner has a problem with the change of your religion then he/she can file for divorce under Section 13(1) clause (2) of the Hindu Marriage Act if he/she converted from Hindu to another religion and ceased to be a Hindu.
The motive of changing religion also matters. A Hindu male cannot change his religion to have multiple wives, it is illegal. The motive should be pious or honest.
Hope it helps