Students from Jammu and Kashmir and Ladakh are not eligible for 15% All India Quota. If you want to participate in All India Counselling, you should furnish a self declaration form. The self declaration form is available in their informaion bulletin at: https://ntaneet.nic.in/Ntaneet/ShowPdf.aspx?Type=50C9E8D5FC98727B4BBC93CF5D64A68DB647F04F&ID=AC3478D69A3C81FA62E60F5C3696165A4E5E6AC4 . When you give a self declaration form you there by declare that you do not qualify for State Counselling and hence are applying for All India Counselling. So if you want to participate in All India Counselling, you will have to for go your State Quota. You cannot apply for both State Quota and All India Quota.