Certainly you are, to qualify for the jee advance you just need to score above than your category's cut off which you did so study hard for advance as the difficulty level of the paper of Jee Advance is must higher than Jee Mains and as you didn't scored that well in mains you need to score good in advance so that your overall can decrease, Don't forget to do the registration for jee advance they have started.

Good Luck