Sin is papa, and penance is tapas.
Upanisands treat Tapas to include an array of ascetic practices: celibacy, fasting, silence, breath control, difficult postured, mortication such as exposure to cold and heat , vaious forms of meditation.
Penance is more important than repentance. Although repentance is important, it alone will not free a person of sin. Manu Smriti, 11.228-234 declares austerity as one of the measures, along with repentance, that the sinner is freed from guilt.
Common penances Hindus perform for reducing accumulated sins or karmaphala are dāna (
