I Know by default, file name length is 128 char, but can this be overridden, because I need my file name to be longer then 150 char.
These are the limits imposed by SharePoint which we can't override.
Character limit for files and folders
These limits apply to files and folders that you add to a synced library folder for uploading to SharePoint. In SharePoint Server 2013, file names can have up to 128 characters. In SharePoint Online, file names can have up to 256 characters. Folder names can have up to 250 characters. Folder name and file name combinations can have up to 250 characters.