Let ℤ n be the ring of integers modulo n. Let Ct , Em , and F r , s respectively denote the cyclic group of order t, the elementary abelian 2-group of order 2 m , and the abelian group of exponent 4 with order 2 r 4 s . In this article, we find the structure and generators of the unit group V ( ℤ n C 2 ) . We also solve the normal complement problem in V ( ℤ n C 2 ) . Additionally, we provide a normal complement of Em in V ( ℤ 2 n E m ) . At the end, we determine the structure of V ( ℤ p n F r , s ) for an odd prime p and establish that F r , s does not have a normal complement in V ( ℤ p n F r , s ) .