Best palces to visit in monsoon in my opinion is more of south.,like Kerala,Tamil Nadu ,u can also visit gokarna a beautiful village in Karnataka state.hope this helps
Most of the travellers do not prefer traveling during Monsoon. But there's different charm of visiting different parts of India during downpour. Coorg, Alleppey, Cherrapunji, Wayanad, Orchha, Udaipur, Munnar, Shillong, Lonavala, Mahabaleshwar, Kodaikanal, Valley Of Flowers Uttarkhand.