What are some roles that anthropologists play in migration?
As pointed out quite astutely by Wawad68, anthropologists are no more or less likely to be migrants or play a role in migrations than members of any other profession. Some anthropologists do travel for their work, but, as all forms of business travel, this is not considered migration.
Anthropologists do study migrants, including both internal migrants, migrants who move from one country to another, and migratory tribes of hunter-gatherers or nomads who have no fixed settlements.
There are two main areas of interest to anthropologists in the study of migration. One is studying immigrant communities and the other is studying the process of migration itself.
A recent area of interest of scholars in cultural studies has been diaspora studies, looking at how a particular diaspora (e.g. Indian, Tamil, Jewish) is affected by the locales to which the group has migrated.
I not sure what you mean by this question, but I will try my best.
After serious thinking, I thought that anthropologists don't have anything to do with migration. They do not affect those who migrate in any way, shape, or form. Instead, they study the movements of different peoples across time and try to figure out what caused them to move.