Hi aspirant, on behalf of your 68 percentile your all India rank will be approximately 499201 so based on your this below are some of the colleges which you can get;

• Delhi Technical Campus, Greater Noida
• Thapar Institute of Engineering and Technology, Patiala
• SGBM Institute of Technology and Technology, Jabalpur
• Malwa Institute of Technology, Indore
• Guru Tegh Bahadur Institute of Technology, Delhi
• Rajeev Gandhi Prodyogiki Mahavidyalaya, Bhopal

Etc.

For more colleges you can try for below mentioned link of college predictor tool;

https://engineering.careers360.com/jee-main-college-predictor?utm_source=qna&utm_medium=jee_cp

Thank You.