Can hear it very weak from 2020z on 6.661MHz CW but Mumbai Radio too strong to get full beacon transmission, only bits and pieces. Managed to get "beacon" and "ru". Maybe Russian? Will compare with the Russian Naval beacon markers on surrounding frequencies tomorrow.
Russian beacons are on 5.152MHz to 5.156MHz CW & 7.038MHz to 7.039MHz CW plus 8.491MHz to 8.496MHz. Should give some indication if 6.661MHz is Russian (Europe & Far East).