No you ain't! 

The cutoff for jee advance for obc is around 74

Hello sanjana!!

congratulations for scoring 72 percentile.

Based on the percentile,your predicted rank would be 249383-279383

However do not worry these are just predictions based on trends and analysis.the final result may slightly vary.

With that rank you may  be eligible for the advanced exam.please prepare well and do focus on basic topics and revise well.

Please see the following link to predict rank and colleges you get :

Https://engineering.careers360.com/jee-main-rank-predictor

Lets hope for the best

Thank you

All the very best