Does it mean that the person is uncertain?osoraku is 'pehahaps' and kitto is 'surely', they're contradictive in terms of assuredness but i see them used together a lot
きっと doesn't really mean "surely" because きっと stands for the speaker's strong conjecture under obscure situations. It's more like "I believe". And おそらく is approximately equivalent to "probably". In this sense, "perhaps" seems too low for おそらく in terms of possibility.