Question

is there any relation between transpiration and rain fall?

Answer 1

transpiration is the process in which all the moisture of tree is taken out by heat of sun (like evaporation from ocean) through the leaf of tree in the form of vapour.
this vapour later condense & become cloud for rainfall..
thus evaporation is related to rain fall

Answer 2

yes there is a relation between transpiration and rainfall....
the water present in the leaves of the plant is evaporates through the leaf by transpiration in the form of vapour.

and hence the water vapour obtained by the process of transpiration form clouds in the atmosphere which results in rainfall.
and therefore both are related to each other.