Database
[{"_id":ObjectId("6165743f5ad72e0cb6fd4a69"),"studentId":"stu1","classes":{"History":{"TeacherName":"T1","Marks":[{"Internal":15}]},"Geography":{"TeacherName":"T2","Marks":[{"Internal":20}]}},"updateDate":ISODate("2021-10-12T11:40:47.156Z")}]
Query
db.collection.update({"classes.History":{$exists:true}},{$rename:{"classes.History":"classes.HISTORY_NEW"}},{upsert:false,multi:true})