I have seen the sentence in a grammar book:
"There are hanging some ripe mangoes TO the twig of the tree."
But earlier I always used ON and FROM in this situation.
Explain (hanging) on, from and to.
Thanks in advance.
Here is how I phrase your sentence:
There are some ripe mangoes hanging from the twig of the tree.
When using 'is' you refer to one noun. When using 'are' you refer to two nouns or a plural noun.
For use of "on" "to" or "from" with the continuous verb "hanging": hanging on to (on to also onto prepositional use indicating position or direction. hanging from (from indicates the origin)
Lastly, it is more common to place the subject some ripe mangos before the verb.