Hello Joshi sir/TGKREDDI sir,
weather mother requested or father requested has nothing to do for DNA test , as per the evidence act 112 of India if a son is begotten during the valid marriage then the son is considered to be the legitimate son of that couple unless he or she needs to establish the proof that they both do not have access.
in ND Tiwari case, the bio logical son submitted the proof's as below
if you look at the judgement of ND Tiwari, rohit sharma proved that her mother Mrs. Ujjwala Sharma and her husband Sh. B.P. Sharma marriage is broken or their relation ship is not existing see the below statement from the judgement
page 25 of the judgement copy states as below
" Documents have been ﬁled by the plaintiﬀ, on the record to establish that both Sh. B.P. Sharma and Mrs. Ujjwala Sharma were estranged in 1970 and subsequently their marriage was dissolved. Both of them have ﬁled aﬃdavits in this regard"
So ND Tiwari was made to undergo DNA test because of the above reason not because rohit sharma or his mother ujjwala sharma's request for DNA.
so in the case of our current queriest his question is weather a mother needs to prove or not, not required to prove as per the evidence act , but if her husband can prove he had no access to his wife then she needs to prove the son's legitimacy by conducting or taking a DNA test.