Hello,

Yes you need to make a new category certificate as 7 years is a very long time so your certificate has expired. Generally the validity of OBC NCL Certificate for Central Government is 1 Year and Whereas Validity of OBC NCL Certificate for State Government is 3 years . You need to renew Both. For Renewal: You should go to a stamp vendor in your District or Tehsil court along with your old OBC certificate and requisite Documents. You can apply from Tehsil court or District Court, The Tehsildar or Magistrate will issue your renewed OBC NCL Certificate.
Online facilities are also available in Some states like in Uttar Pradesh "Lokvani Kendra's" are available for these services.

Thank YoU!