how to know the capacity of a shared drive
Solution 1:
When you go to \ip\c$ you can right click and do properties that will show the C drive of the system you connected too. You can also map a drive to C$ and give it a drive letter and right click it and properties. As a note the "$" is a hidden share so you will never see it from \ip
Solution 2:
As written in one of the comments we must run below command in command prompt
where z is the name of new drive which does not exist in your syst,
net use z: \\path of the folder
You can use x/y instead of z or any other characters
One you run this command, shared drive will be mapped in your system
Now simply right click and then properties, it will show you the size of it.