If my sister works in the US and has a US credit score, will the loan provider consider her US credit score or Indian CIBIL score?

Indian loan providers will consider her Indian CIBIL score, not her US credit score, when she applies for a loan in India.

Indian lenders use domestic credit bureaus like CIBIL to assess creditworthiness. A US credit score is generally not recognized by Indian financial institutions. If she applies for a loan in the US, her US credit score will be relevant there.