I saw the above query resolved in a very easy manner by my team mate which i though of adding here so that it can help some one else and is a common requirement.
So, the question is how we can create groupings based on calculated column in a document library where the grouping should be in in bunches of '50'.
So the easiest solution for acheive the same is to create a calculated column, add the below formula, and to create a grouping based on the calculated field.
*assuming the field name as GROUPFIELD which is a single line of text
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