Thanks for the reply, tasker is not a development environment, it is just an app which lets us invoke different functions of phone on a step by step manner, and even lets us export these sets of actions as apk files.
I have, however, found that there is a very little possibility for banner ads in it. So I have now learnt coding in java and I am now making apps in java.
The answer to this question, if someone else is interested is that tasker can invoke html banner ads with the help of webview object if your preferred ad network supports this format, but to make real and native apps, we need to learn java.
Nokia 5320 --> Nokia 5800 --> Nokia 500 --> HTC Sensation --> Samsung Note N7000