Hi @Amar Agnihotri ,
Thankyou for using Microsoft Q&A platform and thanks for posting your query here.
As I understand your issue , the source transformation in dataflow is giving error : "Malformed records are detected" even though the json is a valid json.
I tried to repro your scenario, I tried with a dummy json having similar format like yours and was able to get expected result and didn't experience any error. For seeking better help, I would recommend you to kindly share your complete json content . Here is the video of the dataflow:
Hope it helps. Please let me know in case of additional queries, Thanks