As you have asked for budget friendly places for adventurous sports, I assume you are ok with sports fees ;) Now depending upon what you want to do, India has bunch of options. Example, for water sports, go to goa after mid October. If you like trekking, go to Kasol and plan for kheerganga which is an intermediate level trekking. If you are into river rafting, Rishikesh is the place where you can possible end up cracking a deal within 1500Rs. In nainitaal, you can go for paragliding. Have a great adventurous trip!