Belgium RP 90 days rule

Hello Everyone,

I am from India and hold a Belgium Resident Permit card. Currently I am in India and will be traveling back to Belgium soon. I have heard of a 90 days rule which says your can enter in Belgium using the existing RP only within 90 days of your exit from Belgium. Is this a correct rule? If yes, is there a way to get any extension for more days or a month ?

Thanks
Tripti

Are you on short or long stay visa?