A Systematic Investment Plan or SIP allows you to invest a specific amount monthly ( or weekly, quarterly). SIP is a planned approach helps you build the habit of saving and growing wealth.
Here is a list of funds that can start small with small ticket SIPs: https://www.jama.co.in/direct-mutual-funds/best-small-ticket-sips/
When you invest, ensure you only do in Direct Plan variants of the Mutual Funds. You then get upto 40% more in long term portfolio size by avoiding commissions and brokers.