This doesn't seem to be possible. India made two tours of Australia in the 1980s:
On these tours, three matches were played in Tasmania:
- A first class match from 11-13 December 1980A first class match from 11-13 December 1980; Kapil Dev did not play in this match.
- A one day match on 14 December 1980A one day match on 14 December 1980; Kapil Dev did play in this match, but it was at the NTCA Ground which is not next to the river. Kapil Dev did hit a six in this match, so possibly there is some exaggeration of the story happening.
- A first class match from 20-23 December 1985; this match was abandoned without a ball bowled.
For completeness, I also looked at India's 1991-92 tour of Australia; the only match played in Tasmania was the ODI against Australia in which Kapil Dev did play but no sixes were hit.