Technical specifications for all of the items mentioned below are given in the above links.
Procure a laptop with the minimum configuration.
Arrange for a broadband / mobile data plan with minimum bandwidth and data size requirements.
Procure a headset.
Procure a USB stick for backups
If your area has power cuts, make sure your laptop battery is good enough, and replace it if there is a problem. Consider procuring either a spare laptop battery, or a UPS if you have a desktop, or if you think any other important device needs power backup.
Configure your laptop: For theory class lectures you just need browsers and conferencing applications (MS Teams)..
Register for Single Sign-On (SSO) by following instructions on CC website /How To's?/Two Factor Authentication (2FA) for SSO. Once 2FA has been enabled, you can login into MS Teams using your ldapid@iitb.ac.in account and an OTP generated by the authenticator app. You can also use your ldapid@iitb.ac.in account to login to Google Drive, Google Meet, etc.
Download and install IITB VPN on your laptop (CC website /Services/Accessing IITB from outside/VPN). You can also install it on your smartphone. This is only needed to access private servers inside IIT Bombay network. You can do this on an as-needed basis.
If you are going to do a lab course, wait for instructions from your Lab Instructor, and only then follow instructions on this website.
Last but not the least, do procure notebooks, pens, pencils. Even in an online semester, you will need these to make your own notes while watching lecture videos, and for working on your homework.
*If you are facing any financial or other situational difficulties in taking the steps to be ready for the online semester, please write to your faculty adviser immediately, unless you are already in touch with some faculty member who is helping you (you should have been contacted by members of a departmental faculty task force created for this purpose - if not, please reach out right away).