Step 1: In the Vedic period, various forms of contributions were made to the king and religious institutions.
Step 2: Bali was the tax collected from the people, usually in the form of a portion of agricultural produce.
Step 3: Other terms:
- Vidatha: social and religious assembly.
- Varman: a title or suffix, not a tax.
- Kara: a general term for tax in later periods.
\[
\boxed{\text{Bali}}
\]