That's a bit of an inversion of history there. It was Pakistan that started hostilities in that region, not India. For two reasons -
1) Continuation of Pak's doctrine that the defence of the east lay in the west. So they initiated hostiities there to relieve pressure on the east, and to ensure that the war wouldn't be over too soon.
2) Pak army had a huge base in Sialkot, and by occupying and dominating the bulge using troops from Sialkot, India's troops in Pathankot would be cut off from Kashmir, which would enable Pakistan to take Kashmir then or later.
The result was the famous battle of Basantar that resulted in a completely unexpected but decisive Indian victory that thwarted Pak's strategic calculations on both the above two points. Quite a few Indian soldiers recieved high medals for valour, including a very young lieutenant by the name of Khetarpal, who's heroics have become the stuff of legends in India's military institutions. (The PA major who killed him, later chivalrously invited his parents to Pakistan and treated them with extreme hospitality and respect.)