Mr. Om Prakash,
I understand your concern but what I have written in my answer is that in the case of Anukul Chandra Pradhan v. Union Of India And Others (Supreme Court Case) is that the petitioner had "CONTENDED" or "ARGUED" that s.62(5) is in violation of Article 14 and 21.
The following is the direct quote from the judgement:
"The learned counsel contended that this is discrimination and violates Article 14 of the Constitution. lt was further contended by the learned counsel that there is violation also of Article 21 inasmuch as the restriction placed on the prisoner's right to vote by sub-section (5) of Section 62 of the Act denies dignity of life."
Even though the petitioner had contended this, the SC still did not give the convicts the right to vote.
If there is still any issue, please do let me know.