Need suggestion

I will be joining a PBC today , the issue here is the CTC is low based on my experience as I was unemployed for few month and I didn't had any counter offer to negotiate the HR and HR law balled the salary. Now there is a high chance of getting a interview call from another PCB who will be paying 5 to 6 lpa more. How should I reach till the point where I get the offer letter from the second company.What are the white lies and points to be put across the HR and Hiring Manager , so that I reach till the CTC offering phase. Note: In the current company which I will be joining today I already hinted the hiring manager that I have been actively interviewing for few companies and after couple of rounds they there were no response from the company.

Thank you in advance looking forward for the suggestions.