Doubt Clearance Thread: UPSC 2021

I got NC OBC certificate dated 17th September, 2017. I mentioned the same date in this year's application form.

Do I need to renew it? 

What's the validity of NC OBC. I see many answers online, some say 6 months, 1 year, 3 years and No validity as such.

Can someone shed some light on it?