Section 32 in THE ADVOCATES ACT, 1961
Section 32. Power of Court to permit appearances in particular cases.—Notwithstanding anything contained in this Chapter, any court, authority, or person may permit any person, not enrolled as an advocate under this Act, to appear before it or him in any particular case.
By giving your signed Vokalatnama to your advocate, you are basically giving the power of council to your advocate to represent you before the court.
If you are appearing in-person then no need of Vokalatnama. If that corrupted lawyer is not giving NOC then also no issue If you appear in-person or you appoint another advocate by giving signed Vokalatnama.
The Vokalatnama is for securing you consent to give power of council to another person to represent you before the law hence the court may ask a petition of your consent in case you don't have NOC.
In case of in-person, no such petition is required.
Please read each of my posts carefully in the following links.
https://www.lawyersclubindia.com/forum/Fight-against-misuse-of-498a-ipc--103100.asp#.U6gslUCm9dg
https://www.lawyersclubindia.com/forum/Best-way-to-fight-against-false-498a-103111.asp#.U6gsRkCm9dg
https://www.lawyersclubindia.com/forum/details.asp?mod_id=104564&offset=1