Group-based object alignment is an essential manipulation task, particularly for complex scenes. In conventional 2D user interfaces, such alignment tasks are generally achieved via a command/menu-based interface. Virtual reality (VR) head-mounted displays (HMDs) provide a rich immersive interaction experience, which opens more design options for group-based object alignment interaction techniques. However, object alignment techniques in immersive environments are underexplored. In this paper, we present four interaction techniques for 3 degrees-of-freedom translational alignments: AlignPanel, AlignWidget, AlignPin, and AlignGesture. We evaluated their performance, workload, and usability in a user study with 20 participants. Our results indicate different benefits and drawbacks of these techniques for group-based alignment in immersive systems. Based on the findings, we distill a set of design choices and recommendations for these techniques in various application scenarios.