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 GRB210326.06 (trigger No 638414549,03h 52m 02.40s , +15d 03m 36.0s, R=39.17) errorbox 57848 sec after trigger time at 2021-03-26 17:26:33 UT, with upper limit up to 17.4 mag. Observations started at twilight. The observations began at zenith distance = 43 deg. The sun altitude is -10.2 deg. The galactic latitude b = -29 deg., longitude l = 175 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1577293 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________| _____________________|__________ ___________|_____________________ _______________|_____|_______|___ ____|________ 57939 | 2021-03-26 17:26:33 | MASTER- SAAO | (05h 55m 27.48s , +07d 21m 35.7s) | C | 180 | 17.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.