Not able to delete a directory with read only files in UNIX?

Not able to delete a directory with read only files in UNIX?

I am trying to delete hidden read only files from a unix directory.I
actually want to delete the directory itself but not able to. It has many
directories within it as well. I am the owner and I should have
permission.
I tried giving permission access it to my own username but not able to
delete or change permission using chmod 777, tried rmdir, rf and
everything as well. Any suggestions?
Thanks in advance.