Even if you do manage to get into IIT/IISc (that's a big if), you'll be starting all over again, with a better package maybe, but still. It's harder than we think.
You're better off either trying for an MBA, or upskilling now. Put in the effort for the next 6 months or a year, become really good at one particular stack and then start asking for referrals.
Be prepared for rejections due to your age factor
( you can debate whether it's right or wrong all day, it doesn't matter. It is what it is) and move on to the next one until you crack the damn interview. You may have to do it all over again even if you get selected, because of the pay factor. Try to focus on Faang/maang companies, because good pay is almost a certainty there.
Honestly, MBA is a better choice at your age considering the context and future. Unless you are really into tech, opt for an MBA.