What will be the problem if i have a taping noise when i start my car until it gets warm mitsubishi 380

A tapping noise that starts out cold and goes away when warm is usually caused by a valve lifter inside the engine. The lifter may be worn/leaking down and will be noisy until it fills with oil pressure. You can try an oil additive ( Lucas Oil Additive ) available at most part stores works very well with noisy lifters. Another noise that can happen cold and go away when warm is an exhaust manifold leak. However, this is normally a ticking type sound rather than a tapping sound.