There's a guide to the English version in the comments below...

Notes

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.)

Rumba nandri!