Density functional theory calculations are used to investigate a series of zigzag and armchair nanotubes of carbon, boron and nitrogen with various values of tube diameters. The nanotubes are studied to understand the effect of the diameter values and the chirality on the energetics, structure and electronic properties of nanotubes. Depending on the composition we observe metallic behavior to be predominant in the nanotubes of carbon-boron (CBNT) and carbon-nitrogen (CNNT). However, semiconducting behavior is observed for the nanotubes of boron-nitrogen (BNNT). The stability of the nanotubes is found to be dependent on the respective chiralities.