Architecture

I think it is not the proper way of asking the question.
Mind that completing a course itself can't get you a nice salary package.
It is your expertise, devotion and talent which actually counts.
Both courses have demand and you can build a great career if you pursue what you are actually interested in

Many students at IIT have taken a drop. It's nothing uncommon, and is very normal.
I, myself, have taken a drop of one year to prepare for JEE and I too had faced this same dilemma few years back.
Also, be motivated throughout the year and try not to lose focus. The pressure on you to perform is great