Hi.
You should take whatever you are comfortable with. Choosing Sanskrit will give you an advantage because you have already studied it. However, if you wish to pursue a new language for your interest, then you should opt for french.
You can also ask your seniors, who took this course, about which language can provide good score and if french course is difficult.
Good Luck
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile