The phrase comes from the Mahabharata verse 13.153.39.
It means 'Where there is Dharma, there will be Victory'. Yato Dharmastato Jayah ( Sanskrit: यतो धर्मस्ततो जयः, romanized: yato dharmastato jayaḥ) is a Sanskrit shloka that occurs a total of 13 times in the Hindu epic the Mahabharata.