Good question. As per an online survey, around 95% of Indians primarily choose to use the money for their dream plans or park in Fixed Deposits (FD). Before I conclude the answer with 1 option let give you a glance at possible options you have 

Retain it as cash – Pay bills, achieve dream plans. If you don't have any expenditure coming your way in at least in 7 days then invest in Liquid funds. It works best for any spending needs in immediate future

Equity funds – Also known as a wealth-creating asset class. If you invest in this type of fund than go for long term for double-digit interest rates. Get enough good returns and that too tax-free.

Debt funds – This is a type of mutual fund. Here you can park your funds in debt related instruments like Government bonds, corporate bonds, commercial paper (CP) etc. Better returns, lower taxation possibilities are the 2 reasons that made me mention this in the list.

Fixed deposit – Considering the current slow market trends currently FD are offering low returns that mostly make an unattractive investment destination for many investors. However, I would recommend you to make an FD if you have very low risk and do not need it for the immediate purpose.

Choose any of the above or explore more possible options from other investment-related discussions on InvestorQ. I find debt and equity mutual funds are best investible options. Consider your risk profile, return expectations and time horizon and pick the most suitable one for you.