Employer doesn't paying salary

Joined small startup office in October 24 as Front end developer, he said in interview that give me 6k so I agreed cause I'm fresher graduated in May24, but he says for first month he gives me 5k only for training period ( though he didn't gave me any training cause he doesn't know how to attach file in email), For October he gives me 3.2k after cutting 3 days of leave, then he gave my November salary 5k not 6k in December 24th and my mind of out of control so I resigned that Day instant, but the Main problem is he didn't want to give me my December pay so please help me with legal actions.