Hi Deepthi, we had visited Mysore and Coorg in 3 days. I have shared our itinerary below.
Day 1
Road trip to Mysore from Kerala
Stay at a 3 star Hotel in Mysore
Evening at Brindavan garden
Dinner from Dosa Palace (Must visit for varieties of Dosa)
Day 2
Chamundi Hills
Nandi temple
Mysore Zoo
Mysore palace
Boating at Karanji lake
Drive to Coorg
Day 3
Rivernear Homestay at Coorg
Nisargadama
Monastery
Shopping
Dubare
River rafting at Dubare
Bandipur national park, shivanasamudra falls, Nagarhole national park, somnathpur, brindavan gardens, golden temple, melukote this places are really good to go for.