I want to Resign i need clearance regarding notice period .here I got depressed it's like I am in jail plz help me anyone to clear this doub

Hey, I joined TCS through TCS Smart Hiring and got selected as a Graduate Trainee under Ignite. As per the process, there's a one-year agreement, and for me, that one year will be completed on 1st August. But I have a doubt — here the notice period is 3 months. So if I resign today, will the 3-month notice period start from tomorrow? Or is it like the notice period can't be counted within the 1-year agreement? Or will the notice period start only after 1st August once the agreement ends? I’m really confused and mentally stressed in this project, someone please clarify this if you know.