Which backend stack will be good to learn now and will be futuristic also?

I haven't used Django, while I have used Node, so I may be biased towards Node. That said, I have used both Python and JavaScript, and enjoy using them both.

I think the distinction between Django and Node is that the former is a web framework and the latter is a JavaScript runtime environment. So one is used to make building web apps easier with Python, and the other is to build backend programs with JavaScript.

So, the questions that you should ask yourself are:
1) What do I want to do?
2) How will Django or NodeJS help with that?

If you answer those two questions and are still unsure, pick one and make a simple project with it.

You'll find that learning one will help you learn the other.

Let me know if that helps. :)

I'm curios about the good things you heard about MEAN stack. Seeing your question is about backend development, it would be good to separate Node from MEAN stack and Python from Django.

My experience is that a framework like Django (Python equivalent of Ruby on Rails which I've used) is better suited for projects where your target database is RDBMS, because of its excellent ORM features.

I use Node for more unstructured database projects, where I need flexibility in both querying and storing data.

So I'd say start with barebones Node, so you appreciate and have a better understanding of the magic Django implements behind the scenes when you move to it.

Forget about the future bit. No matter what you pick you'll always be learning, so the idea that you might pick something that will not be popular in 20 years shouldn't scare you at all. We are in a business of learning. Hence if the stack you learn today becomes redundant tomorrow, it's truly not a big deal. Learn to love learning

As for which to pick right now, try them both and see which one feels good to you

If the goal is to get a bit of a grip on web development, you might want to try and dabble with both and see what you like doing.