Joint House Property

I have taken a home loan for self occupied property, jointly with my father and brother.

The property also register with name of all three borrowers but there is no clear ratio has described in registry. but all EMI are paying from my account .

Requested to please clarify on taxability on interest and principal repayment.

Can I can claim 100% deduction or required to claim in equal ratio i.e 33.%

It will more beneficial to me if reverted with reference of any case law.