Can lunar occultation of Venus occur during solar eclipse?
Yes, but such an event would be very rare. Venusian transits last only about 7 hours, and there are only two in 113 years, So Venus is in transit for about 0.0015% of the time.

So as a back-of-the-envelope calculation, you would need to see about 70000 eclipses before you had a combined transit/eclipse.  There are about 2 solar eclipses a year, so you might hope to get this unusual syzygy once every 35000 years or so.

None are forecast.