The Constitution of India ensures proportionate representation from all regions.

The word 'proportionate' means corresponding in size or amount, or balanced according to a particular ratio. 'Balanced' is the closest synonym among the given options, as it conveys the sense of being in proper proportion. 'Partial' means biased or incomplete, 'unlikely' means improbable, and 'suffragette' refers to a woman seeking the right to vote — none of these match.