vi ~/.bash_profile
Add following 
export ANDROID_HOME=/Users/pushkar/android-sdk 
export PATH=$PATH:$ANDROID_HOME/platform-tools 
export PATH=$PATH:$ANDROID_HOME/tools 
export PATH=$PATH:$ANDROID_HOME/tools/bin 
export PATH=$PATH:$ANDROID_HOME/emulator
Save ~/.bash_profile 
source ~/.bash_profile 
echo $ANDROID_HOME
/Users/pushkar/Library/Android/sdk