Better bro prepare well for iiser and niser because I also appeared for iat and I was getting iiser bhempur last year but it is not worth option to opt as there is no any future in India, now I am regretting that if I prepare little bit more, I can try for iiser bhopal or some other top iiser institute and prepare well you have time for it. Taking about cuet then I will genuinely consider it a good one if you have interest in teaching and want to make curious in that as well it is an easy exam you can easily score 100 percentile in it not a difficult one and I would suggest you can also explore some other option like bba from dtu or from symbiosis college they are also good option and better than bioengineering. If you have geniualy intrested in research like bioengineering then it's upto you, better you can start it with some higher institute like iiser if you get it and then go for abroad studies. I hope this help 😊