What is known about coRL and RL?
By definition, $ \mathsf{RL} $ is a subset of $ \mathsf{NL} $, and so $ \mathsf{coRL} $ is a subset of $ \mathsf{coNL} $. 

Since $ \mathsf{NL} = \mathsf{coNL} $, $ \mathsf{coRL} $ is also subset of $ \mathsf{NL} $. 

Moreover, $ \mathsf{NL} \subseteq \mathsf{P} $.

Please also note that although it is widely believed to be true, whether $ \mathsf{RL} \subseteq \mathsf{L} $ is still an open problem, and so is whether $ \mathsf{coRL} \subseteq \mathsf{L} $. (The obviuos relation is $ \mathsf{L} \subseteq \mathsf{RL} \cap \mathsf{coRL} $.)