Dharaṇendra yakṣa is a revered protective deity in Jainism, commonly associated as the yakṣa of Parshvanath and often worshipped together with his yakṣī Padmavati. However, there is no single, universally fixed “Dharaṇendra yakṣa mantra” that all Jain traditions recite. Mantras and stotras invoking Dharanendra-Padmavati vary by region, sect (Śvetāmbara vs. Digambarā), and lineage.

What you can generally do:

• Many followers rely on the Navkār Mantra (Namokāra) as the main prayer in daily practice, and then include region-specific prayers or stotras that praise Dharanendra and Padmavati.
• If you have a particular temple, lineage, or book (śrāvakī/śrāvaka) in mind, they often provide a specific Dharanendra mantra or stotra in that tradition.

If you want, I can guide you to a version of the Dharanendra–Padmavati prayers used in a particular Jain tradition (Śvetāmbara or Digambarā) and provide the pronunciation and meaning according to that tradition.