Hi Sudhindra,

You can avail both of these quotas in different exams. You cannot declare yourself both domestic student and NRI in the same exam as they have only one category box. However, there are few subcategories which are OBC-PWD, SC/ST-PWD. Such cases are not availing two different quotas but they have one category and the other is the subcategory of that category. But this is not the case with domestic and NRI quota. You cannot describe one as the subcategory of the other. Hope this clears your doubt. 

All the best.