collaboration and red only access

collaboration and red only access

My Team has done basic integration with zoho.

I have few questions

a) would it be possible to do realtime collaboration on a single file by 2 or more people, so that both the changes are reflected, sometimes we end up with 2 different versions,


b) would it be possible to disable the toolbar or hide the toolbar, when we want to make a read only access
locking the second user into read mode when one user is working on it