Since its legal proof of one’s single status, it should be formally written. To exactly know what to state, you may consult with a solicitor or legal matter expert. He can suggest accurate content.
Moreover, the single status affidavit is a sworn document. It should go on like this:
“I, hereby, state or say that I am having a valid Indian Passport bearing number (Passport number) issued at (Issuing place), and is valid from date of issue (Validity from) to date of expiry (Validity to). I state that I am single/divorced/widowed, and I have no living spouse or dependent at present either in India or abroad.”
This content can help you to fulfill the drafting requirement for a single status affidavit.