developing iOS apps for appstore in Mac on Vmware workstations

It is possible to develop iOS Apps using XCODE on a Windows machine running Mac OS on VMWare, but I would advise having at least 8-16GB (or more) of RAM.

Yes, it's possible! Tested on Windows 10 Pro (64 bits) with VMWare 12.5 - Emulating OS-X 10.11.6 (El Captain) and X-code 8.0

yes you can use virtual environment for xcode but i am suggesting you that you should have at least 8GB RAM if you don't then don't go for virtualization because its decreasing the speed.

Yes, it will. But there may be some license issues (You can only install a copy of MAC OS in a virtual environment if you do own a license). You may also encounter some difficulties installing MAC OS on VMWare. But once you get past them, Xcode and the iPhone simulator should work fine.

You can look at this article for instructions on how to install Mountain Lion in VMWare:

Easily Run Mac OS X 10.8 Mountain Lion Retail on PC with VMware Image – Simple Steps