Will someone tell me about any concessions in air fairs in domestic travel in india for 'disabled persons'.

I got to know that there is 50% concession on indian-airlines flights, what about others private players such as airdeccan, spice-jet etc.

Further please tell me whether any "Attendant" is permitted with the physically disabled person to escort him and what about his fairs.

Every airline is different. If you are unable to find the specific information you are looking for on their websites, call the airline(s) directly.