The IAF has never been “opposed” to the Tejas as such but the way the project has been run. The Tejas has not been run with cohesion: one agency has been solely involved in design and testing, another will manufacture it and the IAF will use it and all three are not fond of each other.
The IAF has a major need for a low-end small fighter. I really don’t think there’s any chance of India going for the F-16 — the Pakistan connection, the airframe’s basic age and lack of further production viability are all negating factors.