yes, definitely you belong to defence quota. What you have to do is you have producee a certificate from the authorities.

Here you can check that what are the documents are required or not:

Defence Sub-Category - Candidates need to produce the following certificates:

• Entitlement card in original issued by the Record Officer of the Unit/ Regiment of Armed Personnel of the Armed Forces in case of Armed Personnel

• Widows/ Wards/ Wives of the officers and men of Armed Forces who died or were disabled on duty (both attributable to military service) to produce certificate issued by the authorities.

• Medical records

• Special Pension order and passbook indicating special pension

• Gallantry award certificate

• Ex-Servicemen Identity Card/ Discharge Book/ Pension Payment Order.
• Dependency card issued by the authorities in order to relate the relationship of the candidate with the Defence personnel
• Original Service Identity card
• Certificate from respective CO unit in respect of serving personnel.

for more information you can click on the link given below.

https://engineering.careers360.com/articles/jac-delhi-reservation-criteria

I hope this helps!!

All the best!