Does NLSIU, Bangalore accept IB scores?

Yes, it does although there are some ifs and buts. IB scores come in a little later after the NLSIU admission process begins. So CBSE students have that advantage but I think IB should be fine too. 

• There are ways in which the NLSIU Exam Department converts your IB scores. 
• To my knowledge, those scores do not matter primarily because they have an entrance exam of their own- CLAT. 
• The rank in that exam is what decides your admission. 
• The board scores are secondary. 
• They are looked at after you have cracked the entrance exam. 
• You just need above 50% in your boards if you belong in the general category and 45% in the reservation category.

One of my friends didn't opt for IB for the same reason that they delayed the result and that might result in dropping a year. You can even opt for the exam while you are in the 11th class by choosing the option ‘Class 12 result pending’. That will help you get prepared for the exam and know the level of difficulty. It will act as a practice test for you.