@abc500x500
The permissions are from your Hosting Plan, your Hosting Company or your Hosting server.
Nothing to do with zip or Osclass package.
I wrote this topic for helping some users.
7z software has some ability that files after extracting in linux/dirctadmin and linux/cpanel in host panel files permissions is equal 644 but if we pack osclass with other software it become 755.
I download zip compress osclass script from osclass.org and extract it in my hosting and saw all osclass files permision was 755.
I deleted them and use zip pack by 7zip and after extracting all file was 644.
I had seen this advise several years ago in a Persian forums and afterward when extract a ziped script in myhost and see it 755 i delete them and use 7z software.