Abstract—We present the measurements of masses of two exoplanets and one exoplanet candidate: the candidate we earlier confirmed in the KOI-974 system, a new TESS candidate in the TOI-1797 system, and the well-known hot Jupiter MASCARA-3b. The observations were carried out using the first prototype of the high-resolution fiber-opticspectrograph of the 6-m BTA telescope, and with the BOES spectrograph of Bohyunsan Optical Astronomy Observatory of the Korea Astronomy and Space Science Institute. The MASCARA-3b mass estimates are presented to demonstrate the performance of the new BTA spectrograph and do not differ from the measurements of other authors within the errors. The KOI-974 mass estimate upper constraint is new. Assuming a circular orbit, the exoplanet mass does not exceed 0.16 M_Jup. More complex orbital shapes are not visible at the radial velocity half-amplitude level of more than 20 m s⁻¹, which classifies this exoplanet as the neptunes. Only four observations were obtained for the planetary candidate TOI-1797.01, which is insufficient for its confident classification. Meanwhile, the candidate’s radial velocity values based on these four observations rule out its stellar nature.