IIT Madras has a Google Apps for Education account under the domain smail.iitm.ac.in. Every student has an email ID under the name rollno@smail.iitm.ac.in. Similarly, all faculty have been provided with usernames user@smail.iitm.ac.in. You (as faculty) are free to use this for any or all communication.
On the other hand, using the Google drive associated with this account to store files to be shared with students is strongly recommended as it makes it easy to control who can see your files. Similarly, Google groups can be created easily since all students at IITM have smail accounts.