No its not okay to add BC certificate as an alternative to OBC certificate as rrb NTPC clearly defines the rules of obc certificate which states which the certification must be issued by an authorized authority, like a District Justice of the peace, Collector, Deputy Commissioner, or Earnings Officer and https://publicsectorcompanyjobs68887.blogsmine.com/33112798/railway-recruitment-bangalore-last-date-rrb-apply