Doni , It usually takes 3 month before granting petition for IPR by USPTO.

As Handal said the followings prior to denial for stay by Micron,

Going forward, the parties will conduct fact and expert discovery, but the PTAB is expected to decide whether to grant Micron’s petition well in advance of trial. To the extent the PTAB reaches any conclusions that would have an impact on this case, those can be addressed well in advance of trial or any other final resolution of the case. The expected developments in this litigation going forward are therefore unlikely to irreparably complicate the issues, particularly when weighed against loss of time that would occur if the petition were denied