As per article on Jaguar fighter in sips-aviation. com (www.sps-aviation.com)
IAF jaguar aircraft have an residual life of 15 to 20 years.
Article dated year 2018.
So the upgradation just might be viable. As mentioned by you DARIN 3 has already made the navigation systems quite contemporary. The Honeywell engine is presently the most suitable in terms of increased thrust and reliability. This engine will allow the Jaguar to fly higher, carry more load and reduce take off distance. They also claim higher reliability vis-a-vis the old engine. As per the manufacturer.
But Uncle Sam is trying to fleece us. Maybe intervention at the higher political level can make Honeywell see reason and quote an fair price.
Britain had offered the Adour Mk 821 a few years ago. It is an upgraded version of the Adour Mk 811 engine which presently powers the Indian Jaguars. I believe it has marginally higher thrust.
Best option would be an indigenous power plant. The HTFE(25 kn thrust dry) with after burner. But will it ever be possible within the next few years. We don't even have an flying test bed. Probably an large unmanned drone with 2 engines can be used as a test bed if technically feasible.
