With the development of telecommunications science and the increasing number of problems that require intelligent and reliable technology, 6G communication networks have begun to be widely studied. Terahertz (THz) and Visible Light (VLC) links are the bands that will be used for this network. Due to their wide bandwidth, they are expected to transmit data faster. However, the higher the frequency, the greater the attenuation that occurs during transmission due to rain. This will potentially reduce the performance of the 6G links when applied in tropical areas characterized by heavy rain. Hence, it is necessary to analyze the effect of tropical rain attenuation on the performance of the 6G links. In this study, a multi-variate autoregressive simulation is carried out to generate rain attenuations on such links with statistics obtained from measurements. In particular we look at the performance of base station diversity (BSD) scheme with two base stations serving a user terminal. From the simulation, it can be concluded that under the influence of tropical rainfall for outdoor communication by taking a fade margin of 3 dB as a reference, the link length that allows for the THz link is 2.5 meters and 3 meters for the VLC link, with this short link the use of BSD also has no effect on outdoor communication either with Terahertz or VLC links. Hence, in tropical areas outdoor THz and VLC links are hard to realize, except when the availability or fade margin requirement is made less stringent.