There's a guide to the English version in the comments below...
(H)alva pondra Maambazham
Ingu oodi vaarungal
Pangu pottu thinnalaam.
Mango, mango fruit,
Do you want it?
Come run here
Will eat by sharing.
Notes about the song lyrics by Krithika Ganesh:
Malgova is one of the type of mango. There are many types of malgova, neelam, rumani etc.
Selathu Maambazham = Selam is a District in Tamilnadu (a State of India) & it is very popular for tasty mangoes.
Azhagana = beautiful
(H)alva is a sweet which looks like a thick jelly. (Tirunlveli District is very famous for (h)alva. It is called as Halva or alva).
ungalukkum vendumaa = do u want it?
ingu = here
oodi = by run
vaarungal = come (vaa is singular & vaarungal is plural)
pangu pottu = by share
thinnalam = will eat
Thanks and Acknowledgements
Many thanks to Krithika Ganesh for contributing and translating this rhyme. (Lisa Yannucci put together the English version using Krithika's guide above.)