We have selected suitable 6 exoplanetary candidates from the TESS database which were observable using a network of small ground-based telescopes to collect photometric transits during follow-up observation. We have made a new reduction of TESS photometry using a custom aperture, as well as reducing the ground-based aperture photometry. We have refined the period of transits and constructed O - C diagrams. Mean transit was fitted in all observed photometric filters and we derived individual candidate's physical parameters. Using the colour indices during transit, we hint at the exoplanetary nature of candidates. Three targets TOI-1518b, TOI-2046b, and TOI-2109b were confirmed as exoplanets by other authors during the writing of this thesis. Here, we have provided an independent evaluation and analysis, without any knowledge of their results. TOI-3856.01 is among the targets more likely a substellar object based on my results, but it has not been confirmed yet. In the case of TOI-1834.01, we have proposed another scenario incompatible with the original assumption that it was an exoplanetary candidate and we assume that it is a hierarchical triple system. TOI-3604.01 was also modelled concerning parasitic light in the aperture. Individual models suggest a body too large for an exoplanet.