No. This does not pose any challenge to national integration. Unity in diversity is the special feature of India. Indians may belong to different regions, cultures, castes, and creed. But this does not mean that they are different people. They are one and are proud of being born in India.
Sometimes social conflicts arise no doubt but they are solved in an amicable way. Whenever there is an external threat, all Indians come together. The Kargil war is worth mentioning here.
India fought and won the war. That was the time when everyone was filled with patriotic feelings. There was only one goal, i.e. to win the war and that India did with the help of her brave heroes.