I had set the ANDROID_NDK_HOME as /Users/Shajilshocker/Documents/Android/NDK/android-ndk-r10b using a mac osx application called Enviro
ANDROID_NDK_HOME
/Users/Shajilshocker/Documents/Android/NDK/android-ndk-r10b
cd to path you have to set.
cd
Enter in Terminal: echo "export PATH=$PATH:$ANDROID_NDK_HOME" | sudo tee -a /etc/profile
echo "export PATH=$PATH:$ANDROID_NDK_HOME" | sudo tee -a /etc/profile