At Hostinger, .rar format of archives is not supported. Thus, you can upload it, but you won't be able to unpack it.
Our File Manager supports the following archive formats:
zip, tar, tar.gz, tar.bz2, tar.xz, tar.lz4, tar.sz
If you upload an archive in one of the formats mentioned above, you will be able to extract them 😊
Additional resources: