Adding a lawyer for argument in quashing petition

You can/ should replace your lawyer 

Whether you are adding another lawyer or changing the current lawyer, it is pertinent that you have to obtain NOC from the current lawyer hence you can decide based on the prevailing situation.

Remember that your current lawyer cannot do anything when the listed matter is not reaching for hearing on the date of listing.

The prevailing practice is to obtain NOC from the present lawyer, before hiring a new lawyer. 

Even to onboard another lawyer on the day of hearing, you need NOC from the existing lawyer. 

It is better to replace the present lawyer, if you are not happy with him. 

So, think clearly and decide. 

There was also a judgment from the Supreme Court very recently, just a couple of months ago, that the Court should not insist on NOC from the present lawyer. The party has all the rights to decide who should appear on behalf of him. However, this judgment is against the prevailing practice. It may face some resistance from the present lawyers and Courts. So, it is advisable to take NOC from the present lawyer.