3rd or 4th Rakat۳۔۴ رکعت

In 4 Rakat Namaz, doubt occurs at any stage... Is this my 3rd or 4th rak'at?

Solution... Consider as 4th and finish the salaat.

Soon after Namaz: Recite 1 rak'at Namaz-e-Ehtiyaat standing or 2 rak'at sitting.