If you go for an arts stream there are very less percentage criteria. There is no need to have higher amount of percentage in your 12 standard. If you have got 50% or even less you can get the admission in the college but you should not have failed in the exam. You muat have passed the higher secondary exam. Then you need to be bramch specific that in ehich particular branch you want to go for studies. There are many branches in arts as well like performing arts where in you can go for dance, music and so on amd there are literart arts where you can go for poetry and like things and also photography, painting, journalism so on and so forth. So it depends in your interest and there are institutes available in india or in foreign countries to have a good carreer in arts stream. So you better do not focus on the percentage though it is necessary but it depends on your choice and interest and the institute your are choosing. So follow your thoughts and go with your interest and do well.