@pkgaur which programming language you are comfortable with ?
Here is a brief.
you should be an angel client
sign up for API key here
https://smartapi.angelbroking.com/signup
Request your account migration to API here
https://smartapi.angelbroking.com/topic/33/your-user-id-or-password-is-invalid-errorcode-ab1007/322
Depending on the your comfort programming knowledge, you can choose the different sdk available here
https://smartapi.angelbroking.com/docs/Introduction
for example python SDK has a sample script here
https://github.com/angelbroking-github/smartapi-python
Now you can connect to websocket for data and trading api. These are the rough steps one follow. Other way would be to use other Algo trading platform like Tradetron, marketscanner etc. Above steps broadly covers a general pipeline.