Getting obc caste certificate in up without pariwar register

You can apply for OBC based on the community certificate of your father. 

There is some vital information missing in your post.

If your father belongs to the community falling under OBC of UP state, then you are certainly elgible for the privileges and concessions pertaining to the  OBC community 

You get the rejection letter in writing and then prefer an appeal against the rejection to the District collector.

If your application is rejected there also then you can plan to escalate the matter through legal sources for remedy and relief

Being a State subject Jharkhand government may or may not have declared your caste in the catagory of OBC, check it locally.