First come at Chandigarh after lot of buses are available for bhunter and take taxi cab buses for Kasol from bhunter, hostels are best accomodation for one week
Book tickets from chennai to Delhi
then book a bus ticket from Delhi ISBT to manikaran. Bus boarding point in Delhi is ISBT kashmiri gate and get down in kasol. Manikaran buses go through bhuntar and kasol only. Cost of living is like 300/day if you prefer tent and 350 to 400 if you take a room.
Check out Bhandardara, dist. Ahmednagar. It's an amazingly beautiful place. There's mountains all around. Bhandardara is situated in the midst of Sahyadri range. You must visit this place once at least. Check out The Land Of Wanderlust (TLOW) website..... https://thelandofwanderlust.com/
Hey ! don't miss out the naina peak trek, it's one of the most amazing place to visit. Chowli ki jhali gives the best sunset view , you're not gonna regret it. Tiffin Top trek is also amazing, it's a 4km trek for good 2hrs( two- way).
The time between October and March is known to be the best time to visit Pondicherry city. The temperature in Pondicherry during this time ranges from 15 degree Celsius to 30 degrees Celsius.