Dear Kedar

To enter details of qualification in Step 4 of AIIMS MBBS 2018 application form, in the state, you have to select the state (from which you passed Class 12) from the drop-down list. 

In the option of 'Select Board Name', there are three options in drop-down list, namely CBSE, ICSE and OTHER. Since you haven't passed Class 12 from either CBSE or ICSE board, but have passed it from Goa Board, you can select the option of 'OTHER'. 

I hope it clears your query. 

All the best for exam!