NTA has issued a clarification that you can fill any State details against All India 15% State Eligibility field. You can mention any State except for Jammu and Kashmir and Ladakh as they do not participate in All India Counselling. Irrespective of the State you mention there, you will be eligible for 15% All India Counselling of all States except for Jammu and Kashmir and Ladakh. But if you are equiring as which State's domicile do you qualify for, it will be Maharashtra.