Hinduism and Mesopotamian religion both dating back to a few thousand years ago, are few of the ancient religions on the planet having a lot of mysteries and secrets about the creation and evolution of the universe, also creation of mankind and activities on earth in ancient past. Though the Mesopotamian religion is no longer in practice, Hinduism is still practiced by more than a billion people across the globe.
The influence of Hinduism at its peak was stretched beyond modern-day Afghanistan, and there were a lot of trading activities between Indus valley civilization and ancient Mesopotamia, resulting in the exchange of goods, culture, and beliefs. But, similarities between those civilizations were beyond the exchange of trade and culture, something that descended beyond earth, un-imaginable by modern humans, which resulted in a lot of similarities between the scriptures of ancient Hinduism and the Sumerian religion.
These are some of the mysterious similarities between these ancient religions:

Manu/Anu saving life forms on earth, and vishnu/Enki as a form of fish guiding the boat

In both mythologies, the current creation was restarted after a serious flood, which was created to wipe out existing life on earth. Anu and Enki (Sumerian mythology), Manu and Vishnu (Hindu mythology) playing a prominent role in reinstalling life on earth.

Donation of gold to gods:
an Hindu idol decorated with gold and other precious stones

Gold has played a major role in both civilizations, the ritual of gifting gold and other rare resources to gods can be found in both religious scriptures, and is continued to be a part of Hindu rituals, where the idols of gods are decorated with gold and other ornaments as part of the tradition.

Tree of life | kalpavriksha:
tree of life or kalpavriksha and Ashur/ devendra on top of the tree

According to Hinduism books called Puranas, the tree of life is a sacred tree, when pleased by prayers it can fulfill all of the wishes, and is guarded by Gandarvas in the city of Amavarvati( city of immortals) which is the city of Indra/ Zeus/ Ashur. It was obtained by gods in the process of the churning of the ocean, the process which is also seen on Sumerian mythology on the Temple of Ninhursag at Tell al-'Ubaid, in modern-day Dhi Qar Governorate, Iraq.

Enki and Vishnu:

Enki with his companion eagle
vishnu on his companion eagle
Though the role and affiliation of these gods are different from each other as in Hindu mythology he (Vishnu) is considered to be the Supreme Being among trinities, while in Sumerian mythology he is described as the god of water, knowledge, mischief, crafts, and creation. Shockingly, all the characteristics of Enki are also mentioned in different avatars of lord Vishnu. There are a few similarities between them; Both Enki and Vishnu played a vital role in preserving life on earth at the time of the great flood, and both can be seen with an eagle as a companion.

Devendra and Ashur:
Devendra/Ashur on his vehicle

Devendra is said to be the lord of devas, while Ashur was claimed to be the head of the Assyrian pantheon, as per the ancient scriptures the above-mentioned races descended from the heavens. Both Devendra and Ashur possessed a unique spacecraft and celestial weapon that was used to fight the demons.

Usage of face masks:
Hindu goddess slaying Mahishasura (Asura with buffalo mask)

The deities from both mythologies wear some sort of animal masks to cover their faces.