Hello Syamsai gudla,
If you got 123 marks out of 300 marks ,then the expected percentage is in between 97.7-97.9 . And also you can predictor your rank by using the below link.,you can get the percentile/rank depending on the previous years details.
JEE Main Rank Predictor - Know your expected IIT JEE Main 2020 Rank by ...
Hope this helps you...
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