Many studies have explored the effect of grouping and task distribution strategies in collaborative learning in the conventional condition, for example, grouping based on student's learning style, gender diversity, and motivation, but few studies have investigated the impact of heterogeneous grouping with mixed gender and ability factors and the distribution of roles and tasks on members' engagement and collaboration in the IVE environment. This study proposed external scripts that were composed of grouping strategies and distribution strategies. The former includes Mixed Gender and Ability Grouping (MGAG) and Mixed Gender Grouping (MGG), while the latter contains Role-based Task Distribution (RTD) and Freely Distribution (FD). The scripts serve as a heterogeneous grouping and distribution procedural guide for collaborative learning in an Immersive Virtual Environment (IVE), which has the potential to address issues such as homogeneous competencies, collaboration confusion, and conflict among group members to meet the needs of IVE-based collaborative learning. This study used a quasi-experimental research method to explore the effects of IVE-based collaborative learning on students. The results of the experiment which contained 77 junior high school participants from 2 classes showed that: (1) MGAG can stimulate students' motivation(d = 1.55); (2) RTD can improve students' engagement(d = 0.66) and reduce their cognitive load(d=-0.92); (3) There is no significant interaction between MGAG and RTD in motivation, engagement, and cognitive load. Therefore, the study recommends MGAG combined with RTD to be stressed in IVE-based collaborative learning.