You can follow these simple steps to change your SIP:
Website
Here's a short video to guide you through the steps:
App
Home page → Mutual Funds (either from the center of the screen or from the bottom tab) → Goal in which you have SIP running → SIP Center → SIP Actions → Change SIP Date
You can also refer to these screenshots to guide you:
1. Click on the Mutual Funds section.
2. Click on the goal in which you wish to change the SIP date.
3. Click on "SIP Center".
4. Click on "SIP Actions".
5. Click on "Change SIP Date"
6.Change the SIP date to the date of your choice.
7. Confirm the new SIP date.
Please note that you would be able to set up a SIP from your dashboard up to 1 day prior to the scheduled SIP start date. For example, if the scheduled SIP start date is January 7, you can set up the SIP till midnight on January 6.
If you wish to change more SIP details you can refer to these FAQs
Add/Remove funds (change any funds)