I had written neet two times one in 2019 n other in 2020 (I qualified my puc in 2019) I didn't get great marks in neet 2020, n now have joined bsc can I write neet in 2021 n get into iisc for ug courses

As of now, there is no upper age limit for NEET and there is also no cap on the no.of attempts at NEET. So as long as you fulfil the eligibility criteria for NEET, you can appear for NEET in 2021. And to be eligible for NEET, you should have completed your 12th, passed in all subjects and secure a minimum aggregate of 50% in Physics, Chemistry and Biology. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST. Now if you belong to OBC Category, the Category you belong to should be also listed in the Central OBC list. Or else you will be considered as General Category and so you have to secure a minimum aggregate of 50% in Physics, Chemistry and Biology. This 50% is inclusive of the Theory and Practical marks scored in Physics, Chemistry and Biology collectively. You needn't score 50% in Physics, 50% in Chemistry and 50% in Biology separately. You need an aggregate of 50% or 40% depending on your Category as an aggregate in Physics, Chemistry and Biology. And along with Physics, Chemistry and Biology, you should also have studied English as one of the core subjects in your 12th. If you are looking to prepare for NEET on your own, you can try our NEET Knockout package which is available at: https://learn.careers360.com/knockout-neet-may/ . It has as many as 17 years previous question papers with almost 5000 videos and concept videos. This is backed by Artificial Intelligence and so you can study at the comfort of your house at your own pace.