Kaveri saga is one reasons for delay for Tejas. Tejas was a very ambitious project with India actually starting to develop many technologies simultaneously and that too without experience. It is a truly a bold project.
It would be like you, waking up one morning, and your dad tells you "Ok, you build a car" So in same way, you get your friends to involve in the project and put them in teams and give them responsibility. Now same as you, India had to develop Kaveri from scratch and without experience, IAF was hell bent on not to accept Tejas at any cost since they wanted "imported Maal" Still due to Govt Support, DRDO ADE and other agencies went on.
Engine tech is one of the difficult technology to develop and absorb, And in a way we had to absorb the knowledge for the past 6 decades in less than 2. To help us with it, GTRE had taken the help of SNECMA (SAFRAN) who were employed as consultants, all they did was take money and did nothing to help the development. after all would you really help your competitor? Maybe GTRE was naive to expect that, As I said, France is not a friend, its only there for business and our money.. Rest all is BS. If India rejects the Rafale you can see reactions from France.
None of the engine manufacturers will be eager to give the tech readily. Which will in a way mean almost giving 4 decades of hard earned knowledge, India expects Russia and USA to provide this technology Both these countries are expected to get a bigger share of Indian defence pie. France being the loser in this case. USA is eager to sell F/A-E/F. It is a nice clean and very capable plane that can fight to its strengths, further its also a carrier based plane and hence we automatically address the future need of Indian navy.
I myself would love to have just PAKFA/FGFA and Tejas Mk1A induscted by 2020, no other plane. As that would give balance to IAF and also give the edge to take on PAF and PLAAF. Rafale is fighter of last generation and the best it can do is hold up against planes of 4th Gen. As I said before, every plane has its strengths and tactics are developed for that. Suppose India inducts F/A-18, hts strength is avionics and of course AMRAAM. so tactics for this plane should be to hit the enemy in BVR and not make the mistake of getting into WVR fights, how difficult can this be? If its plane like MiG-35 or Su-35, the pilot can take down plane like Rafale with eyes closed or sipping afternoon tea. Rafale has its strengths, but its not the best of 4.5th gen. It is one of the "also participated .." types.
Thus to come to the point that Pratt and Whitney, GE, and Rolls Royce are now moving to more developed engines which are being used in F-35 and so it makes sense for them to share the earlier tech with India and create a partnership thats beneficial for them in coming future. India would be looking at 3000 engines for its upcoming projects. And tha is a very big number for whoever gets that deal. By this year end, we shall have the likes of GE setting their plants in India for production of F-414 engines with Tech transfer and ensure partnership with India for long term strategic benefits for India and USA.