There is a possibility of you getting admission at LNCT Bhopal in the ECE branch if you have got 51 marks in JEE Mains 2021.
Although you might get LNCT if the cut-off lies in this range it is not possible to say for sure because the cut-off varies according to the marks that you and your competitors have secured in JEE Mains.
Although you should note that the ECE branch is not that great. The faculty base is not good. You will get little to no help from the faculty.
It’s better if you choose CS at LNCT or LNCTS. That way you will have more placement opportunities. Most IT companies visit the campus for placement. The core companies visiting the campus are very less in number. So, if you take ECE, your placement opportunities will be limited.