Most disabilities shouldn't stop anyone from traveling. There are more options and resources out there than ever before. However, it must be noted that India -- despite the fact that it has such a high population of people with disabilities -- is not well geared for travelers with disabilities. Destinations are far from wheelchair friendly, and it is hard enough for an able-bodied person to negotiate the crowded, filth-strewn, and potholed streets, where cars, animals, and rickshaws drive at will. Access to historical monuments is also difficult (though you will have the small reward of free access). Certainly you would need to be accompanied by a traveler familiar with the destination, and you must carefully sift through the accommodations options, only a handful of which have facilities specifically geared to travelers with disabilities.
Organizations that offer a range of resources and assistance to disabled travelers include MossRehab (tel. 800/CALL-MOSS [2255-6677]; www.mossresourcenet.org); the American Foundation for the Blind (AFB; tel. 800/232-5463; www.afb.org); and SATH (Society for Accessible Travel & Hospitality; tel. 212/447-7284; www.sath.org).