I have rank 271 in gate 2023 and I have applied for 10 top IITs and IISc and got no offer from IITs in the first round, except offer from AI at IISc. That is how much a written test helps or destroys. Everybody thinks 70 percent weight for GATE and 30 percent for written, so all toppers get the offers it does not matter much with written. But that is not the case, 30 percentage weight given to the paper of 30 marks, that actually means each ten marks in written directly increase your overall percentage by ten where as every 143 gate score contribute to ten overall percentage. If you do very bad in the written exam then there is very less difference between someone who has score of 1000 from a guy who got score 850. This makes lot of difference. Goodluck.