You can check the complete Karnataka domicile criteria at the official website http://kea.kar.nic.in/ugneet2019/UGNEET_instructions.pdf . To give you an idea of what the criteria say:

1. The Candidate should have studied in Karnataka for a minimum period of 7 years in any Government Recognised Institute of Karnataka including 11th and 12th
2. The Candidate should have passed 11th and 12th from Government Recognised Institute of Karnataka or either of the parents should have studied in Karnataka for a minimum period of 7 years
3. A Candidate who has studied in a State outside Karnataka can be eligible if either of the parent's hold domicile of Karnataka. In this case, the mother tongue of the said parent should be either Tulu/Kannada/Kodava. If this is the case, the Candidate should give a Kannada Language test.

So if you are planning on studying 11th and 12th in Maharashtra, to be eligible for the State Quota, you have to take the Kannada Language Test.