The DNA (Deoxyribonucleic acid) contains four nitrogenous bases. These four nitrogenous bases are Adenine (A), Guanine (G), Thymine (T), and Cytosine (C). The sequence of these nitrogenous bases determines the gene. The Adenine pairs with Thymine, and the Guanine pairs with Cytosine. These nitrogenous bases are joined together with hydrogen bonds.
The base pair of TCCAGG will be AGGTCC. Hence, the answer is 'AGGTCC'.