APSRTC buses will be available. Its not frequent but 2 or 3 from Kondapuram. Suggest you to go by bike and I'm sure you will enjoy the beautiful journey with good surroundings. The Roads are in great conditions. Try to book accommodation in Gandikota in advance or carry a tent and sleeping bag with you.
Mahashivarathri attributed to Lord shiva has always been a grand event of celebration in Velliangiri hills Coimbatore. I will share a few offbeat spots to visit in Coimbatore so that when you travel next time to see if it is suitable for your travel. Indira Gandhi national park
Coonoor visit
Vaidehi waterfalls
Topslip a lovely hamlet
Kodiveri dam
Meenvallam falls
Dhoni hills.
I think you should not look for any agency or packages.. goa is nice small state with easily available vehicle facility for rent at every shop...you can travel by yourself here and enjoy the time
Manali in Himachal Pradesh is perfect for a solo budget traveller. I had visited that place as a solo traveller. You can get so many budget hostels there. From there you can opt for various adventure activities or go to trip to Ladakh. Even you can just enjoy watching views, without doing anything.