Om Namo Bhagavate Vasudevaya
Twelve syllables, and for that reason called the Dvadashakshara — the twelve-syllable mantra. It is the central mantra of much Vaishnava practice.
What it says
Namo is the bow; bhagavate is the dative of Bhagavān, the possessor of bhaga — fortune, majesty; Vāsudevāya is the dative of Vāsudeva, son of Vasudeva, which is to say Krishna. Read together: oṁ, I bow to the Lord Vasudeva.
Where it comes from
It appears through the Bhagavata Purana, where Prahlada and Dhruva are both described as repeating it, and it is used at initiation in several Vaishnava sampradayas. It is older in written record than the maha-mantra.
How it is counted
One repetition per bead, 108 to a mala. At twelve syllables it is among the longer mantras kept as daily japa, and a mala unhurried takes twenty minutes or more.
Some traditions count it on tulsi beads specifically. Practitioners who keep both this and the maha-mantra usually give them separate sittings rather than mixing them in one mala.
Counting it here
Because this one is long, Root Jaap sets it above the ring rather than inside it, so the words stay legible and the number stays large. Everything is kept on your own device.
Count Om Namo Bhagavate Vasudevaya →Opens the counter with this mantra chosen. No account, works offline.