Yes

It's a decent branch

Actually don't see the preparation.

If you are seeing the competition in gate it's less so it's advantageous.

Instrumentation engineering definitely has good scope in future don't worry

https://www.google.com/amp/s/engineering.careers360.com/articles/how-prepare-for-gate-instrumentation-engineering/amp

GATE examination provide a Bridge between Graduation and Master's/PSU Jobs. If you get Good score in GATE (i.e. >50), there will be higher chances to get admission in colleges like IIT’s and NIT’s and also in PSU sectors.

You have good scope if u appear for GATE INSTRUMENTATION ENGINEERING. You can apply to indian Oil,Hindustan petroleum and many other PSUs.

Start preparing soon for good marks.