India just imports all the parts from outside countrys and like a jigsaw puts them together inside India and gives them a Indian name, if u look at Indias imports its becomes very clear very fast whats going on
for LCA India first tried to make Kaveri engine which failed spectacular fashion, then India turned to USA for F404 engine
India got
17 x F404 in 2004
and after Kaveri engine failure they then imported
24 x F404 in 2007
and then switched engines to
99 x F414 in 2011
so now they have 41 x F404 and 99 F414 engines, which has meant further delays in development for LCA cus they changed engine!!
infact India still imports turbo props from Canada, USA and Ukraine
from Canada they imported
181 x PT-6 in 2011 for PC-7 trainers
from Ukarine
100 x AI-20 in 2011 for An-32
and from USA
112 x TPE-331 from 1986-2011 for Do-228
Not many have mastered in Aircraft jet engine, and it is not like such technological know how are easily available, for example a South Korean MBT K2 Black Panther, they use a German mil after their own effort to design one was not satisfactory, now that is for a MBT, that do not make K2 Black Panther less South Korean and we are discussing Aircrafts, with a very few successive engine manufacturer in competitive market. Even one of the non US competitor of MMRCA proposed a model with a GE-414 engine on it. Using imported components upon an Aircraft does not make an Aircraft not belonging of that nation.
If you say Kaveri engine failed to delivery the require performance, then yes it is, but if you say Kaveri engine is a failure no it is not, it have succesfully completed high altitude test in Russia and still development have not stopped,
The fact that Kaveri is unable to deliver the required optimum performance is criticised but the project is not discouraged. It may see other application and the technical know how gained is treasured which may see future usage, like for a UCAV, Kaveri is proposed to be used upon it, Acquiring foreign made UCAV for a nation might be of problem due to MTCR restrictions, and that is where the effort done upon Kaveri is expected to bear its fruit
A domestic technology and product in a war fighting machine is asked for so that your decision making in a war scenario is not influenced or subjected to a foreign nations approval, it gives you the liberty to make your own decision without any clause attached as you wont be bound by any clause or agreement.
But in the other hand using lower performing products for a weapon might give the enemy an advantage in a war scenario.
So decision of selecting the right weapon for her forces is decided upon that basis.
But technology and ability reached are not in vain when their are scopes for application.
A Kaveri fitted Tejas would have been great but not at the expense of Aircraft performance and Indian Air Force wont be happy if they are forced to accept a less able aircraft when their are chances of getting more form the product.
It is a good news that aircraft engines are available in the Market to put in an indigenously made aircraft, other wise the only option available would be to put the lower performance Kaveri on Tejas.
Using foreign made engines upon domestic aircraft is not limited to India Aircraft industry solely.
But manufacturing a domestic product (may be with imported components) is certainly limited to a few among the rest. If it cannot be termed as best, it can be atleast termed as better then mere buying foreign final end products.