B2 visitor visa questions

[v_aapi]

Q: My parents have their interview on Nov.16th 2004 in Delhi. My mom is a government employee and can only stay for 3 months but my father is a businessman and want to stay longer than 3 months, may be 4-5 months. They both have their interview together, I am not sure if it is okay to quote different time lenghts for their stay in US during their interview. Can it be counted against them. Is there any minimum period for which visitor visa is granted? Is is 6 months?
Q: I read about form # 20 on this website. Somebody had mentioned that if one of the parents is independent business owner then he or she needs to fill this form. I have no clue as to what this form is and where I can find more details about this form.
Q: Similarly, I am not sure what people mean by letter of senator and how it can be obtained? Is it required for visitor's visa?
Q: Is it okay to fax or scan letter of invitation and the letter to consulate to my parents or embassy requires to see the originals?

Any suggestions or inputs will be greatly appreciated.

Thanks,
Akanksha

[immihelp]

1. It is ok for them to stay different durations. There is no minimum period for visa, but usually at least 6 months.

2. Please post URL where you read it on this website.

3. Don't worry about it right now. It is not required.

4. Send original.