As far as I known, Mr. Vayalar Ravi's entire family practises Christianity. I really doubt whether he brought up his son and grandson as Hindus.
If Mr. Vayalar Ravi were a devoted Hindu, he wouldn't have done what he did and this controversy would not have started. Even if he is hurt by the PUNYAHAM ceremony, why should he make such a big issue out of it? There are many other issues.
I sincerely believe he is just playing politics. This is my very SINCERE assessment. I mean it. It all depends on what you SINCERELY think about Mr. Vayalar Ravi.