To get started with the DOSP-OS sources, you'll need to get familiar with Git and Repo.
repo init -u https://github.com/DesiOS/Desi_Goodness.git -b nougat
repo init --depth=1 -u https://github.com/DesiOS/Desi_Goodness.git -b nougat
repo sync --force-sync --force-broken --no-clone-bundle -jxx (Ur Choice)
. build/envsetup.sh
lunch desi_<device>-userdebug
mka desi