In Jain Dharma, it is not “which is better,” because Brahmacharya and Tap both are essential and support each other.

• Brahmacharya (celibacy/chastity) is part of Samyak Charitra (right conduct). It controls sensual passions, protects the mind, and makes all other vows steady.
• Tap (austerity) is the active effort to burn karmas. It includes:

- External Tap: anashana (fasting), unodari (eating less), vritti-parisankhyana (limiting intake/means), rasa-parityaga (giving up taste-stimulants), kaya-klesha (bearing hardship), and sanlinata/sallekhana-type restraints as appropriate. - Internal Tap: prayashchitta (repentance), vinaya (humility), vaiyavritya (service), svadhyaya (study), vyutsarga/kayotsarga (abandonment of body-attachment), and dhyana (meditation).

How they work together

• Without Brahmacharya, Tap easily turns into pride or restlessness; the mind is not pure, so austerity gives less spiritual fruit.
• Without Tap, Brahmacharya lacks strength; austerity gives energy and clarity to keep the vow firm.
• With Samyak Darshan (right vision) as the foundation, Brahmacharya stabilizes Charitra, and Tap accelerates the shedding of karmas.

For householders (shravaks/shravikas)

• Practice Brahmacharya as the fifth Anuvrat (sexual restraint within dharmic limits).
• Add Tap according to capacity: fasting on holy days, aayambil/ektana, limiting items, svadhyaya, pratikraman, and daily meditation.

For monks/nuns

• Perfect Brahmacharya is mandatory.
• Regular, well-guided Tap (both external and internal) is integral to purification.

Digambar and Shvetambar viewpoints

• Both traditions uphold Brahmacharya as a core vow and Tap as sixfold (external and internal). The emphasis may differ by text or monastic discipline, but there is no contradiction in principle: both are indispensable and mutually strengthening.

Simple guidance

• First establish right faith and basic vows.
• Keep steady Brahmacharya according to your stage of life.
• Add Tap gradually, with humility and proper guidance.
• Aim for purity of intention; results in Jainism come from inner purity, not from show.

So, neither is “better.” The best is their harmonious practice under right faith: Brahmacharya keeps you pure; Tap burns karmas and deepens that purity.