Hey,
South India is perhaps one of the most underrated places when it comes to travelling. South India has lots to offer! Places like Gokarna, Kodaikanal, Coorg, Ooty, Murudeshwar, Banglore, Mysore are all wonderful but for the month of August 2018, I would suggest you to visit the god's own city KERELA. Rather, Munnar to be more specific, the reason being August 2018 - October 2018 is the season of blooming for Neelakurinji flowers which bloom once in 18 years offering an breathtaking view to the touristts. The entire hills would be covered in the heavenly blues and purples offering a site which is simply perplexing! Apart from that you can also consider Banglore - Mysore - Ooty - kodaikanal/ Coorg circuit, I had done that in the previous year which was amazing as well.