Rinisha same problem here... Even i want to join through GATE. This may help you. U have chances of getting Anna University with your gate score.Usually 85% seats are alloted for state quota and remaining 15% for All India quota.Having a score of 40-50 will help you to secure a seat in  Anna University if you belong to the state.For others according to the previous year cut off a score of 50 above will have a high chance.You can also write TANCET 2019 to increase your chances.The first preference will be given to GATE and then TANCET qualified students based on the order of your merit. Hope this helps.