How to select a coffee powder for preparing Turkish Coffee? This is what I can get here: 
http://www.devans.in/product.html

What kind of roasted (mild/medium/strong/very strong) powder/beans should be selected for Turkish Coffee?  

Can the coffee powder meant for preparing Filter coffee be used for Turkish coffee?

I'd prefer a sweeter taste of coffee rather than bitter.
This is something that is likely to depend somewhat on your preference. That said, when I cannot get purpose-made turkish coffee, I usually use a very dark roast for turkish coffee, mixing it with a bit of cardamom (about one tablespoon to every twenty tablespoons of powdered coffee).

From the offerings you have available, I would recommend the Very Strong "Arabica french roast". You may very well find that this is too bitter for your palate. If so, I would recommend sweetening the coffee using sugar, rather than going for a lighter roast, but again, you may find a lighter roast.

If you have one of these roasts in your house already, I would recommend starting out by trying that, then playing around with spicing it with cardamom, and sweetening with sugar before getting a different type of coffee. This will help you determine what way you want to go with your finished brew.