Could I read file from my pc running windows XP with NTFS5 file system, from a machine under windows 95 on the same network?

Surely you can do it, if you configure Networking properly, i.e. create Network Share on WinXP for the folder where file is located and assign proper access rights to the share.

After performing these procedures if you can lookup WinXP machine across the Network you'll be able to see this network share from Windows 95 and access files inside.