You seem to be asking in Gujarati/Hindi style:

“Tirthankar nām, nikachnā (nikachit) karmone khatam karvā je tap kartā hoy, e tapnā nām English māṁ?”

In Jain dharma, Tirthankar Bhagwān destroy even nikachit karma (the very heavy, almost unavoidable karma) mainly through very intense tapas (austerities) – especially the classical 12 kinds of tapa.

Below are their names in simple English:

6 External Austerities (Bahya-tapa)

1. Fasting – complete abstinence from food (Upavāsa)
2. Eating less – taking limited food (Unodarī / Alpāhār)
3. Giving up tasty food – simple, non‑attractive food (Vṛttiparisaṅkhyān)
4. Controlling desire for taste – not insisting on special food (Rasaparityāga)
5. Living in lonely / difficult places – forests, cemeteries, solitude, etc. (Vivikta-śayyāsana)
6. Bearing physical hardship – heat, cold, insect bites, etc., with patience (Kāyakleśa)

6 Internal Austerities (Abhyantar-tapa)

1. Repentance / remorse for sins (Prāyaścitta)
2. Humility – respecting all, removing ego (Vinaya)
3. Service to saints / elders / sick (Vaiyāvṛtya)
4. Study of scriptures (Svādhyāya)
5. Meditation – concentration on soul, true nature (Dhyāna)
6. Renunciation – giving up possessions & attachment (Vyutsarga / Tyāga)

Through these 12 tapas, practiced at the highest, purest level, a Tirthankar completely destroys even nikachit karma and attains Keval‑jñān and finally Moksha.

(Both Digambar and Shvetambar traditions accept these 12 types of tapa with very similar names and meanings.)