Why are you so worried! Usually in large MNCs, all these processes go in a completely procedural way, can’t be played with.
In this case, since you resigned, rather than they terminating or putting you on PIP etc, you have nothing to worry. First action of intent to leave, is from your side, so you have an upper hand, just in case they play dirty (which I am sure they won’t).
Also, you should not bother much about work now. Spend less time in work, or max 8 hrs. If you are not able to finish assigned task and they ask about it, just give some polite diplomatic reply, something like “yeah it is taking a bit more time, but I am trying my best”.
Focus on your interviews. Once in notice period, it is organisation’s fault that they force people to stay with them, so don’t work at full potential, just be polite and don’t argue, but no need to work full potential.