Hon’ble Apex Court in this judgment, had rejected the application of a Deputy Manager of a Company to appear and argue on behalf of the petitioner-Company.

A natural person can, of course, appear in person and argue his own case personally but he cannot give a power of attorney to anyone other than a person who is enrolled as an advocate to appear on his behalf. To hold otherwise would be to defeat the provisions of the Advocates Act.

Who can be Party in Person?

Section 32 of the Act, however, vests discretion in the court, authority or person to permit any person who is not enrolled as an advocate to appear before the court and argue a particular case. Section 32 of the Act is not the right of a person (other than an enrolled advocate) to appear and argue before the court but it is the discretion conferred by the Act on the court to permit any one to appear in a particular case even though he is not enrolled as an advocate.

… and more…

We make it clear that as regards artificial persons like a company registered under the Indian Companies Act, or a registered co-operative society, or a trust, neither the Director of the Company nor member of the Managing Committee or office bearer of the registered society or a trustee has a right to appear and argue on behalf of that entity, since that entity is distinct from its shareholders or office bearers or directors. However, it is the discretion of the court under Section 32 of the Act to permit such person to appear on behalf of that entity.

From Para 7,

7. There is a distinction between the right to appear on behalf of someone, which is only given to enrolled lawyers, and the discretion in the court to permit a non-lawyer to appear before it. Under Sections 29 and 33 of the Act only those persons have a right to appear and argue before the court who are enrolled as an advocate while under Section 32 of the Act, a power is vested in the court to permit, in a particular case, a person other than an advocate to appear before it and argue the case. A power-of-attorney holder cannot, unless he is an enrolled lawyer, appear in court on behalf of anyone, unless, permitted by the court under Section 32 of the Act, though of course he may sign sale deeds, agreements, etc. and do other acts on behalf of someone else, unless prohibited by law.

Citations : [2011 ACR SC 2 2269], [2011 JKJ SC 3 56], [2011 JT SC 7 559], [2011 KLT SC 3 498], [2011 RCR CIVIL 4 252], [2011 SCALE 7 413], [2011 SCC 15 449], [2011 SCR 7 846], [2014 SCC CIV 2 617], [2011 MWN CR 3 290], [2011 AIOL 469], [2011 RCR CIVIL SC 4 257], [2011 KLT 3 498], [2011 JT 7 559]

Other Sources :

https://indiankanoon.org/doc/170747848/

https://www.casemine.com/judgement/in/5609af02e4b0149711415575