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.
Just to add my pinch of salt as razunny said you have to find your taste initially try an espresso (whole beans) and grind these coarser (or have them ground) than you would for other coffees
