grep command does not work to find a string inside a file utf-16 format

Issue

• grep string file_name works but for a specific file dont work. Use the file command to check the format and it is in UTF-16.

file file_name.txt file_name.txt: Unicode text, UTF-16, little-endian

• While use grep command with other file format (ascii) it works fine.
• Try to use dos2unix command to change the format but dont work.