Topological indices (TIs) are mathematical codings of the molecular graphs that predict the physicochemical, biological, toxicological, and structural properties of the chemical compounds. To evaluate the physical and chemical properties of molecules, numerous TIs have been studied in the literature. In chemical research, a nanostructure is one of the most important and frequently studied substances. It was created using molecular-scale engineering mechanisms. Zagreb indices (ZIs) are the majority studied by TIs. TIs are categorized based on their degree, distance, and polynomial. Connection-based topological indices (ZCIs), one of these TIs, are extremely important. In this article, we compute several connection-based topological indices for carbon nanotube graphs. We obtain first ZCI (1st ZCI) and second ZCI (2nd ZCI) and modified first ZCI (1*st ZCI), modified second ZCI (2*nd ZCI), modified third ZCI (3*rd ZCI), and modified fourth ZCI (4*th ZCI). Moreover, we compute multiplicative ZCI (MZCI), named as first MZCI (1st MZCI), second MZCI (2nd MZCI), third MZCI (3rd MZCI), fourth MZCI (4th MZCI), and modified first (1*st MZCI), modified second (2*nd MZCI), and modified third (3*rd MZCI) for carbon nanotube graphs.