posting a set of maps from a study by Col. John H Gill who studied the 1971 war. will illustrate gains/losses were quite paltry except in kargil-turtok side. india would need a far greater effort to have ripped into Sindh... maybe usa set a red line ? https://muse.jhu.edu/article/180990 

its almost impossible even now due to dense water networks to enforce any decisive battle in punjab and in kashmir due to terrain. this leaves gurdaspur-chaamb where we are historically always on back foot and rajasthan-kutch where we have done nothing much to scare the paks yet.

we need airborne divisions, considerable helicopter airlifts and much better armour forces & artillery to rip through sindh. the kit & logistics tail we have can at best do some limited gains before running out of steam. the new punjab-jamnagar expway may help build more pressure

but pak will also respond with chains of new fortifications in sindh.