Is it possile that rain drops contain eggs of fish?

It's possible but very unlikely. During a hurricane or tornado, fish could certainly be swept up, and that includes their eggs. Thus, the rain would seem to contain fish eggs (or frog tadpoles, or whatever else got swept up). There have been reports of water-spouts that caught up a number of fish and their eggs, but again, this is not a common occurrence. In fact, scientists note that reports where it was said to be "raining fish" are usually caused by severe storms, rather than by fish living in the sky-- there is no credible evidence of fish living in the sky.