Where to invest surplus

I have a business that generates around 4-4.5 lakh per month. From that revenue, i have my family members as employees and i pay them:

50k : mother 40k : father 25k : sister in law 58k : wife

A total of 1.73 lakh goes into salary and I can’t give them more than that, I can’t give myself a salary since I am already employed and come in the 30% tax bracket.

I do all my travelling and expenses from the current account.

Still, there is a surplus of around 2-2.5 lakh in my current account every month sitting there, where can i invest it or any expense that i can do that might pay off in future.