I have installed iTerm2 and Oh-my-zsh. However there is a weird question mark that is coming ever since I have changed ZSH-THEME to \"agnoster\".
Attaching the screensho
This has fixed the issue. Just select Use built-in Powerline glyphs and use Inconsolata for Powerline font.
Use built-in Powerline glyphs
Inconsolata for Powerline