You can invest in Equity SIP in two ways amount based or quantity based. All brokers allow you to create multiple SIP request, each request should be either amount based or quantity based, you can mix and match different types in one request.
- An amount based SIP: In this, you define fixed amount for your investment. It is calculated by dividing the SIP amount by Last Trading Price + Buffer (3%) per share. Rounded of quantity will be finalized by the Equity SIP engine to take the buying call before the Equity SIP Order placing.
- Quantity based SIP: In this, you define a fixed quantity of shares/ETFs for your investment. On the specified date, the Equity SIP engine will check available fund in your account and place a buy request.
All these requests are submitted to exchange on availability of funds in your trading account.