Hello Saket Kumar!
Thanks a lot for your question.
There are 20 NLUs in India. While 19 of them accept CLAT score, one - NLU, Delhi - conducts its own entrance exam known as AILET.
Just like IITs and IIMs the quality varies immensely within the 20 LNU. To get an admission in top NLUs, such as NLSIU, NALSAR, NLIU, NUJS, GNLU etc is extremly competetive, while its relatively easy to get admission in other NLUs.
Based on past trends, some experts have predicted the cut off's for CLAT 2018 which ranges between 125 to 148. i.e. the minimum you should aim to score to get admission in the top 3 NLUs is 125 out of 200 marks. These are of course predictions. To get more details and previous year trends of cut off ranks for all the NLUs, please click on this link - https://law.careers360.com/articles/clat-cutoff
For NLU Delhi, you should aim to score between 90-100 (or above) in AILET if you belong to General category. For cut-off details in other categories, please refer to this link - https://law.careers360.com/articles/ailet-cutoff
Feel free to ask if you have another query.
All the best.