Acceptance of cash

I am a businessman and i have current account in 2 banks. My debtors are insisting me to collect cash from their premises which is around 20 - 25 Lacs. They will surely give me 500 &1000 notes. I use to account everything and nothing is black. The question is whether i should accept the money in cash and deposit into my account? We are in need of the money as we have to expand our business.. Please guide