If disulfiram tablet doesn't cause vomit on drinking alcohol than can we give him a ipecac syrup for vomit for making fear in alcohol drinker?

I would not advise ipecac use in anyone when it can be avoided. Once considered a standard part of any households safety kit it has been removed from that position in the US for decades. It is known to have a selective toxic effect to heart muscle fibers. Chronic use has been marked by significant heart damage. Get the person into a behavioral therapy group.