The affix ac comes after the word rahas when it follows 1. anu 2. ava and 3. tapta in a compound.,
Thus अनुरहसम्, अवरहसम्, तप्तरहसम् ॥,
Adhyāya 5 · Pāda 4 · Rule 81
The affix ac comes after the word rahas when it follows 1. anu 2. ava and 3. tapta in a compound.,
Thus अनुरहसम्, अवरहसम्, तप्तरहसम् ॥,