What is the JTAPI JavaScript version for AES 10.1 , where we can download it or please share the SDK download link .

What have you read that leads you to the conclusion that there IS a javascript version of JTAPI?

I believe that the closest you will find is the Avaya Client SDK, which exposes some call control functionality but that is intended for a client acting on behalf of a single user. It is not meant for server side functionality although I suspect you may be able to twist it into something that will work that way to an extent.

https://www.devconnectprogram.com/site/global/products_resources/avaya_client_sdk/overview/index.gsp

I'm looking for web socket (aescticonnector/websocket) based java script SDK , we have integrated for JTAPI v8.1, so similarly for version 10.1 which java script sdk we need to use?

What have you read that leads you to the conclusion that there a javascript version of JTAPI exists?
There isn't one offered by Avaya.