Should I remain silent during the Tashahhud if the Imam says the taslim before I complete the Tashahhud?

The final Tashahhud is one of the pillars of prayer. So, if the Imam pronounces the Tasleem before the worshipper completes his Tashahhud, the worshiper should not follow him. Rather, he should first complete his Tashahhud, as it is an obligatory act (fard). As for invoking blessings upon the Prophet (peace be upon him), scholars have differed regarding its status, with some considering it a pillar (rukn), others an obligation (wajib), and others a Sunnah. The command to seek refuge from four things after the final Tashahhud has led some scholars to consider it obligatory. Therefore, it is safer (more cautious) for the worshiper not to pronounce the Tasleem until he completes the Tashahhud, invokes blessings upon the Prophet (peace be upon him), and seeks refuge from these four things.