I am an Indian citizen and was issued a B1 visa, valid for 6 months, in last December from the Dubai US consulate. I travelled to the United States and exited before the i94 expired. The previous purpose of visit was elective clerkship and I have reapplied once more for the same reason .Will I be issued a visa again ?If so ,are the chances of getting a 6 month valid visa higher than receiving a ten year valid visa?
US visa validity for a B visitor visa is normally 10 years, unless the reciprocity table for a country specifies a shorter duration. Reciprocity in this circumstance means that the US issues shorter validity visas for a country's citizens if that country issues shorter validity visas for US citizens.
In the case of India there is no reciprocity issue and Indian citizens can get 10 year validity visas.
However, the visa validity can be limited in some circumstances. If the consular officer believes that your circumstances are OK now, but might not be OK in the future, then you may get a shorter validity visa. One example given in the Foreign Affairs Manual is of a high school student about to graduate but who has not yet been accepted to a university. He might qualify for the visa now, but might not qualify after graduation, so he would receive a visa for a shorter duration.
For example, in a country with 10-year visa reciprocity, this could apply in the case a 17 year-old high school senior who has not yet been accepted to university and seeks to travel on a family trip with his or her family, when the consular officer believes the applicant overcomes 214(b) at the time of the interview, but would wish to re-interview the applicant in the future. That could constitute reason to issue a visa with less than the full 10-year validity permitted by the Reciprocity Schedule. In contrast, in the same country, a 17 year-old applicant accepted to the country's most competitive university and who plans to later attend medical school may be an applicant to whom a consular officer would approve a full validity visa. These examples illustrate that, as with all visa adjudications, the consular officer must make a case-by-case determination concerning visa validity based on the applicant's specific circumstances.
So there are no "chances" to get a 10 year validity visa. It is all based on your own personal circumstances. You might think about whether there is anything in your personal circumstances which may make the consular officer think you qualify now, but might not qualify later. Perhaps your residence is about to expire and has not been renewed?