Ensure you have closed and reopened the software (Word/Photoshop) after installing the font. Sometimes a system restart is required for the software to recognize the new font.
This is the recommended method for most modern users.
macOS might warn you that the font is "legacy." You can usually bypass this by selecting "Install Checked" to force the installation. Why is it so "Difficult"? Because Walkman Chanakya 902 is a non-Unicode font
Unicode/Rendering considerations
Drag and drop the chanakya.ttf file directly into the Fonts window.