Hey,
Domicile generally refers to your homethe state you consider your permanent place of residence. You need to stay in a state for atleast ten years in order to get the domicile of that state.
Domicile depends upon several factors and the important ones among them are:
1. Residence proof,like,Ration Card;Voter ID;House Tax;Tax receipt;Documents of the property owned by you or your guardian
2. Age Proof,like Birth Certificate or 10th/12th marksheet
3.Proof of Identity,like Aadhar Card or Pan Card
In your case,your home state would be Uttar Pradesh,if you have your 10th documents and the residence proof to prove you have stayed there for atleast 10 years.
Hope this helps.
Good luck.

See if you have a domicile certificate of Uttar Pradesh, then your home state should be uttar Pradesh only. It helps you alot during college admissions as well as finding jobs in uttar Pradesh as well. Go for UPSEE exam and you might get a good college in Uttar Pradesh. I hope it helps