You are a Jee aspirant & you want to appear for clat 2018. You cannot be attained the two different things at same time. As you know that IIT Jee & Clat exams are totally different from each other. So, either you can select IIT Jee or Clat exam as your interst.
Many students who qualify the Jee exam but they couldn’t clear clat exam so it’s not a easy task to qualify clat. Make your preparation strong for one individual exam.