I am familiar with programming culture.
I want to start learning 3d games development.

I want to know which language is most suitable for sustainable games development-
directX or openGl or c++ or some third language???

Please guide me!
Thanks & Regards

DirectX and OpenGL are not programming languages. They are APIs (application programming interfaces, wiki it if you want) that can be used with other programming languages (like C++).
As far as which one is better, don't know if I can help you too much there.

The only real programming language I know is C++, and I'm currently learning to use DirectX with it. If you're a fan of things be open-source and multi-platform (or a Microsoft hater), then you might want to go with OpenGL. DirectX is strictly Microsoft. As far as how good the actual APIs are, I don't think that DirectX is really that much better or worse than OpenGL (but that's just from what I've heard - I've never actually used OpenGL).

As far as what language to use, C++ is probably the way to go, though as I've said, I haven't had too much experience with other real programming languages.