Yes you can get admission in COEP with the state quota from Maharastra.

You need to make sure that during counselling you carry domicile certificate or birth certificate for proof, as your 10th and 12th certificates will not be valid.

For more information regarding obtaining domicile certificate you can go through this link

https://www.wikiprocedure.com/index.php/Maharashtra_-_Obtain_a_Domicile_or_Residence_Certificate

Also you have to be sure that you secure 75% in 12 boards if you fall in general category and 65% if you fall under SC or ST category.

All the best and feel free to ask any query!

Yes definitely you can get admission into COEP whether or not you studied from Maharashtra. The only thing you need to carry is the domicile certificate and you can get into MHTCET or you can apply through JEE mains 2019 through Counseling. Do remember about the documents you need to carry.