Yes, it is possible to get into a top-rank NLU such as NLSIU, NALSAR or WBNUJS, etc. But this all depends on the strategy you have prepared. There are some CLAT achievers who join for a crash course. They study 8 hours a day rigorously. So, to get the same performance in 1 month is nearly impossible.
So, it is suggested that you join the tuition classes for a crash course and dedicate 8 hours of your time to CLAT preparation. Cracking CLAT will only be possible if you work hard.