Аннотация:MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 210401A ( Fermi GBM team, GCN 29739) errorbox 77156 sec after notice time and 77165 sec after trigger time at 2021-04-02 20:43:09 UT, with upper limit up to 17.2 mag. The observations began at zenith distance = 80 deg. The sun altitude is -51.3 deg. The galactic latitude b = 0 deg., longitude l = 357 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1581695 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________| _____________________|__________ ___________|_____________________ _______________|_____|_______|___ ____|________ 77256 | 2021-04-02 20:43:09 | MASTER- SAAO | (17h 29m 04.89s , -34d 09m 47.6s) | C | 180 | 17.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.