I'm looking at your latest question, ignoring the irrelevant title and introduction.
Where could I get infos related to communication between Android and Microchip.
That's not a Stack Overflow question. That's something you look up using a search engine and the product documentation. The web has tons of information on client/server setups, in pretty much all the languages you could care for. Forums and chat rooms can work for that too, if you're looking for pointers.
I'm trying to make a Android application which would be a telnet server since my Microchip unit is a telnet server.
Ok, this would be a good start for a Stack Overflow question, except for the issue that the logical structure doesn't grok: if you've got a server on your Microchip, the logical thing to implement on your Android device would be a client, not another server. Let's assume it's a typo to try and make sense of the rest.
My server is working all fine.
Ok, this looks good too... but hey, wait a second. Which one of the devices is that? Let's hope the rest of it clears this up.
All I need is an app that can receive and respond correctly.
And this is not a Stack Overflow question (or at least, doesn't appear to be). It reads as if you're asking for someone to recommend you an existing app that could work with your Microchip device. Or your phone. (At this point I'm completely confused about what part of what you've got you're asking about.)
And that's the whole of your question. I don't see how anyone could help you there.
You need to explain exactly what you are trying to do, as clearly and simply as possible.
What device are you programming on - the Android one or the Microchip one? Both? What part of that have you successfully implemented so far? What part, specifically, is giving you problems?
Show the relevant parts of what you've got, even if it doesn't compile (show the compiler errors in that case), doesn't work (show the error messages/stack trace/problematic behavior), or is only pseudo-code. Or show the client part if you can't figure out how to get the server part to work with it (someone might explain a different way of writing the client part to make the server part more obvious/easier to code). Or vice-versa.