I have a offer from a particular company. They are asking me to fill I-9 form. I am confused whether this will be restrict me from applying and getting offer from other companies. I am not sure whether I will be joining that company or not.
You should not fill out an I-9 until after you accept the job offer. However even after you accept the job and begin work you will not be restricted from applying or getting offers from other companies. Good Luck.