India was offered to join the JSF program, but this hasn't been taken up by India. The deal would also involve designing and assembling components of the a/c in L-M's massive research plants in India. Even without official Indian participation, no doubt non-classified work on the JSF will be done in those plants anyway.
The main reason for India's rejection being that America is seen as far too unreliable an arms supplier. The knee-jerk reaction to the Indian nuclear tests is proof in and of itself. Granted, the relationship between the two democracies is changing quite fast (the proof is in the exponential growth in military ties between the two nations)
Furthermore, India is already committed itself to a 5th generation a/c; a joint Indo-Russian fighter PAK-FA, and an indigenous multirole attack a/c the MCA (Medium Combat Aircarft.) The Tejas (LCA) will fill in the light multirole role (replacing eventually -21s, -27s, Jags and M2ks)
India, as can be seen in its latest defense porcurments all across the board from navy to army to air force is changing from a simply buying arms to jointly developing them with its former arms suppliers.
In terms of a/c, the IAF inducts 'souped up' versions of all its a/c, often fitted with a variety of Indian, French, Israeli, Russian and British components, as evidenced in the Su-30MKI all the way to the MiG-21 Bison (with again customized indigenous avionics and BVR, datalinking, etc. capabilities) which demonstrated its ability of being a great more fitting a match against the F-15 than was popularly expected, in the COPE-India exercise with America.
Even the M2Ks, -29s, Jags, -27s, and Harriers that fly with India show the same types of customization.
Hindustan Aeronautics Tejas: