She has completed her step1 and step 2 ck.
Now she wants to give her step 2 cs and apply for residency.
A lot of indians, pakistanis, nigerians try to do step2cs, step3 and the interview process in one stretch. This can be difficult on a B1/B2 as this is limited to a couple of months and extensions are dicey. I do understand that you guys try NOT to go back to the US consulate in your respective countries if you can avoid it, but if you want to stay for the long period of time that all those actions require sometimes an alternative solution has to be considered (one alternative is to come on a F1 visa for the Kaplan review courses, if you have enough money to burn you can stay on that for many months).
Can anyone tell me the type of visa she has to apply for?
I heard it will be business or tourist visa(bvisa).
A B1/B2 is usually sufficient to come to the US for the exam alone.
Is it easy to get that visa?
You have to show ties to your home country such as family, property, a place to live etc. as well as the money for your trip to the US.
One thing US customs and consular officer can smell a mile away is b#$*%*t. So, don't try to tell them that you are planning to take a 9 month vacation and oh on the side you are trying to take the USMLEs and all that on $900 in your foreign currency account.
And if she comes on that visa, can she apply for residency and convert to h1b.
Since 9-11, changing status from visitor to anything other is eyed with great suspicion. The terrorists used this trick to escape closer scrutiny. So since then, if you intend to start to study (F1/J1) or work (H1b), the goverment wants you to tell the immigration officer at the border. They will note in your passport that you intend to change status, if you have that note (and the entry in the computer), changing status is allowable. It is not like they arrest you if you do it without the notation, but you might have to show up for an interview.
if she wants to marry in between, say, to some gc holder or h1b visa holder or citizen,will it become a problem in the future?
One thing they don't like AT ALL is people coming on a visitors visa, getting married a week later and applying for a different status the next day. Marrying an H1b doesn't do anything good or bad to your status per se. Rather the opposite, on the H4 visa as spouse of H1b, it is possible to stay here for the longer time and do interviews etc. According to a new memo, H4 time does NOT count against the H1b 6 year clock anymore.
Marrying a GC holder who lives in the US can be a problem. If you need to take a J1 visa, you have to proove that you are a non-immigrant. Marrying a US citizen or PR (who lives in the US) can be considered an expression of immigration intent.