u/ChampionshipT

Hi guys, I need some advice for a friend who has been laid off recently in March from a company. (Not IT) He has been told that his contract is going to be terminated during March due to some issues in the project. It was garment related job and they were short with materials. Then again the owner said to work for the April month and he will provide a salary for the April month as a compensation. Now the owner says that he cannot pay until the project completes and he is not going to pay the compensation until that. He has mentioned that if the project does not succeed then he will not getting any compensation at all.
It was just a verbal agreement and he has some messages sent from WhatsApp about the deal that they had.
Is there any possibility to convince him and get the salary? Can you please help me to understand the Laws of a situation like this? Is it worth of trying this with a Lawsuit?
Thanks in advance for the help and advise