The best workaround that I could find was to use db.collection.update(); though i had to go thru a long procedure of excel and making similar queries for each and every row just after which i realized I could have used db.collection.find().forEach();
So to cut down the solution use forEach to iterate and execute db.collection.update() with condition matching the data and field to update. I formatted the query as a string and then used eval();
If you found a shorter way please do lemme know..!!