Hello student. If you had gotten seat in ece then t would have been easier to get cse in 3rd round of councelling. Since its electronics and instrumention, it is a bit tougher and chances ae less to get cse in 3rd round. But stiill ouu can try. Even if you donot get this cse in 3rd round, you will be given the option of sliding after 1st year if you score well.