external pendrive is read only When i plug my external pen-drive(FAT32) in macbook pro(OS: Mojave) it is getting detected but nothing can be copied on pendrive. 
Seems like there has been some restriction on my office mac so that pendrive remain read only.

Need help in removing read only protection from pendrive.

PS: This problem can be solved by changing registry in Windows but dont know  how to remove it on mac.
Are you sure it's FAT32, and not NTFS? MacOS can read NTFS but not write to it natively.

If you can't write to a USB drive formatted as HFS+ (Mac's native format), then I would agree that your office had put some block in place. How to over-ride that may not be easy or possible, depending on how they have implemented and what level of access you have on the computer.