Transcription:
Then pañcadaśakṣarī - the most important mantra. If you want to forget about all these mantras, you can do that. But don’t leave the pañcadaśakṣarī and don’t leave the Guru mantra.
You say, you don’t have the time to do this and you don’t have time to do that. You don’t have to do that. You can even forget the pañcadaśakṣarī and Guru mantra and just stick to one single mantra called so’ham, it’s part of the Guru mantra.
You can even get rid of so’ham, just keep your attention on “om”.
So in order of importance: “om”, then “so’ham”, then Guru, then pañcadaśakṣarī. So you have the levels of importance. Then, if you have time, all the others.
Source: Guruji's Sri Vidya Course Lecture