Well what really is considered "winning"? In 1965 there was no real winner and at the risk of getting called names i would say india had the upper hand. Pakistan would not have been able to sustain the war any longer so they had to go for talks. If india wanted they could have sustained the war longer but probably wouldnt have achieved much after taking heavy losses itself.
At the end of the day, both sides took heavy losses. India had captured some 700 sq miles of Pak territory and Pak captured around 200 sq miles. Both sides called it a win.