Here are the addresses for Musee Musicals - 73,Anna Salai, Chennai-600 002 and Lakshman Shruthi - 72,2nd Avenue,Off 100 Feet Road, Ashok Nagar, Chennai - 600 083. You might want to try Ritchie Street, I guess it is cheaper there, however, you will have to buy the cable and the jack separately and then get it assembled. I have bought a guitar power cord from a shop called Sudharshan Electronics in Ritchie street. It costs Rs 115 ( Rs.50 for 2 metres cable; Rs. 40 for 2 mike jacks, soldering charges - Rs. 25)

@sindhuja - Can you provide the addresses for the two above?

Check out Lakshman Sruthi, Ashok Nagar. Or Musee Musicals, Mount Road.