Does elfa 4th gen hiv test can detect all hiv subtypes including groups n , p and subtypes crfs ?! please answer.

Probably yes...: ...and probably it doesn't matter. These rare HIV types are pretty much absent from most countries except tropical Africa. If you and your doctor remain concerned, additional tests can easily be done to check for such infections. But most likely you needn't worry, especially if not exposed in Africa or sex or needle sharing with a recent African immigrant.