Which government college can I get on 8695 general and 2427 obc rank in upsee 2019 from mechanical branch?

Based on your rank you can get certain government Colleges. As you have mentioned that  you are in OBC category so you get some extra benfits over other. The government Colleges where you can get admission are:
1. Chhatrapati Shahu Ji Maharaj University Kanpur
2. Lucknow University
3. Bundelkhand University Jhansi
4. Rajkiya Engineering College Sohnbhadra
5. Rajkiya Engineering College Kannauj
These are the government Colleges where you can get chance. You have good opportunity to get a good government college. So go through these Colleges. It depends on the cutoff list.  The cutoff list depends on the number of students appeared in the exam and the level of paper whether it is easy, moderate or difficult. As you are interested in Mechanical branch so you can get these Colleges.