Today Dell engineer replaced our motherboard, and this fixed issue with DRAC.
New motherboard uses older main BIOS and DRAC BIOS versions:
main: was 3.0.0, now 2.0.11
drac: was 1.70.21, now 1.41.13
Now DRAC works, and, yes, it does have web interface.
P.S. Sadly, but this won't fixed another issue we've with H200 controller or it's linux driver mpt2sas: https://bugs.launchpad.net/linux/+bug/777441 (ClxAdmin, if you're using Linux on this server, which linux distributive/version you're using?)