Hi,
If RAR contains only RAPID then it may be for SI request RACH form UE.refer 38.321 for more information
UE used NDI bit to decide the transmission is new or re transmission .When UE ignores this bit and continue.
Handover RACH will be initiated as Contention free, RNTI will be included in Mobility info. But while doing RACH What will be the RNTI value included in RAR? Will this be same as Mobility RNTI?