no formal grace period. but seems 10 days is not a problem.

好像只有一个月(不很确定)，不用马上回国，但是动作要快，keep住身份，赶紧转f1或找下家什么的。不论此帖是为谁问的，希望能顺利解决问题。

Strictly, there is no grace period. But you can locate a job in couple of weeks, you should have no problem transferring H1B. You might have the option to change the status to B2(visiting for pleasure visa), but it will take much longer to getting the working visa. Best of luck.

No grace period. Legally, you are required to leave the country immediately.

If you are laid off today, you should submit application to change your status at the same day (F1, F2, H4, or B1/B2).

If you fail to do that and apply another H1b a couple of weeks later, it is most likely that you will be required to leave the country and get another H1b visa. It is very risky to do that.

In addition, if you stay in the US illegally more than 180 days, you will be subject to 3 years bar.