If IV is sent/shared with the cipher text then where is the need to randomise the IV? I have been reading to understand the need to randomise the IV but have failed to understand this yet.

Could someone please explain why do we need to randomise the IV if we somehow need to send the IV with the cipher text because the receiver, even though has the key would not know the random IV.

Therefore, wouldn't an adversary who has access to the cipher text can see the random IV for each message? 

Why isn't it better to agree on a fixed IV like the key and not send it over with the cipher text?
Randomizing the IV makes it so that you can send the same plaintext twice, and still get different ciphertext. If you don't do that, an adversary will be able to tell whether or not two messages are identical. This can provide a way for an adversary to infer the contents of messages without actually directly attacking the cipher.

A randomized IV prevents this, even though the IV itself is typically made public, since there's no way an attacker can use the transmitted IV to decipher the message without also knowing the key.

It's a lot like salting passwords, really.