Dharam Chakra Tap means the wheel (chakra) of the dharma being turned or spread through tapas (austerities/renunciation). In Jainism:

• Dharam (dharma) refers to the righteous path and universal law taught by the Tirthankaras.
• Chakra (wheel) symbolizes the spreading or turning of that righteous path—i.e., the teaching of Jain dharma that rolls out to all beings.
• Tap (tapas) signifies ascetic practices, self-discipline, fasting, meditation, and other austerities that purify the soul and generate spiritual energy to uphold and spread dharma.

So together, Dharam Chakra Tap expresses how sincere ascetic effort and disciplined conduct help propagate and uphold the Jain path of right conduct, right knowledge, and right faith. There can be slight differences in emphasis between Digambar and Shwetambar traditions, but the core idea remains: tapas supports the teaching and realization of dharma.