According to Hindu Mythology, Vetalas are snake-like creatures. How are they similar to Medusa?
I'm afraid the source you mentioned is on a TV show called Lost Girl.
The best source for finding relevant info on the Vetala is the Kathasaritsagara especially book 12
The twelfth book is important as it contains the plan and details of a collection of tales extremely popular in India, existing both in Sanskrit and in all the vernacular dialects, called the Vetala Panchavimshati: twenty-five tales of a Vetala being related by a sprite, who haunts cemeteries and animates dead bodies, to Vikramaditya, king of Ujjain, according to the usual version, to Trivikramasena, king of Pratishthan, on the Godavari, according to the Kathasaritsagara.Kathasaritsagara Wikipedia
Further information may be gleaned from the The Imperial Gazetteer of India Vol.2 a great historical reference book, which is available online for free and linked at the bottom of the quote.
A collection of pretty and ingenious fairy-tales is the Vetalapanchavimsati, or ' Twenty-five Tales of the Goblin,' stories supposed to be told to king Vikrama of Ujjayini by a demon inhabiting a corpse. They are known to English readers from Sir Richard Burton's Vikram and the Vampire. Another collection of fairy-tales is the Simhasana-dvatrimsika, or ' Thirtytwo Stories of the Lion-seat,' supposed to be told to king Vikrama by his throne. Both these works are of Buddhistic origin. To the same class belongs the Suka-saptati, or ' Seventy Stories of a Parrot,' represented as narrated to a wife whose husband is away on his travels. The Imperial Gazetteer of India (waybackmachine)
The Indo-Europeans did not only share a common language, they also shared a common mythology and worldview. You will find much more similarities when comparing Hindu and i.e. Norse, Baltic, Welsh and other pre-christian European mythologies. I.e. all Indo-Europeans believe in a cycle of life, death and rebirth cf. https://en.wikipedia.org/wiki/Proto-Indo-European_mythology#Otherworld (this wikipedia article has severe quality problems, only as a side note)
With the spreading of monotheism this unifying worldview was disrupted, because of Muslim influence even the Hindu worldview is not purely Indo-European anymore, i.e. the non-dualistic concept of universal balance and order Brahman turned into the male (dualistic) deity Brahma (strong monotheistic influence).
The Indo-European names for the non-dualistic concept of universal balance and order are Rta (Vedic), Veritas (Roman), Urda (Norse).
Linguistics is an important tool in the attempt to reconstruct the (proto-) Indo-European mythology, however it is also often too interpretable