Why would i be given clopidogrel (plavix (clopidogrel) ) for tia when warafin is reversible? is warafin not indicated in in tia for carotid artery disease ?

Differences: Clopidigrel has been carefully studied for prevention of stroke and heart attack, and seems to work well for local obstruction of blood vessels, but warfarin is an anti-coagulant designed to prevent blood clots at a distance from entering the brain circulation. Warfarin does not seem to be risk advantageous for local TIA, and likely your doctor has made a reasonable choice.