Shakthi engine of LCH/ALH & Vikas engine of PSLVs are of french origin. We failed to develop new variants from these two engines ( either France didn't provide enough ToT or we arr technically incapable to do it, i beleive later will be the actual cause.
@Picdelamirand-oil be honest why India failed to follow up these two engine projects? Is it because of insufficient ToT or leck of technical capabilities of India ). We started searching for new partner for IMRH engine, you should ask why we didn't develop or started work for IMRH engine?
Similarly, ISRO is using a cluster of two vikas ingine on GSLV mk3 as on today instead of using an upscaled vikas engine. This two engine configuration seriously had a bad impact on GSLV mk3 as it limited to mount only two strap on engines on either side, thus limiting the lift off capacity.