That's the problem with Tejas; it won't work.
M53 is substantially larger&won't fit, and it is also much less efficient(SFC) - and for tejas, range is specifically a problem(mk.1)/key requirement(mk.2). It is designed to work specifically off small, powerful yet efficient engine. Which is why the can't jump off this horse, unless they pay someone for developing their specific version(which they did - to GE).
Basically, to make M53 work, they should ve bought M2000 line back then. Which they of course should've and know that. But now, there's no going back.