1. Having unnatural s*x is a penal offence under Section 377 IPC. But, your wife even after making such allegation cannot put you behind the bars. There are several ways for the accused to come out of such allegations. So, do not bother about such threats.
2. But, you can be arreted under Section 498-A IPC, if she files complaint of harassment for dowry. If such thing happens, then you must be ready to take anticipatory /regular bail.
3. I also want you to discuss with your wife and try to settle in India, in the event you get a good job here. Otherwise, if possible, convince her and take her there where you are working. You see, marriage and purpose of marriage is solely both the husband and wife live together and share pleasure and pain together. Just within one year, you fly abroad, then what is the purpose for your wife to have married you and live a spinster life? Is it good on your part to ask her to stay away from you, even after marriage, because you want to earn tons of bucks. Had you talked with your wife before marriage that you would give preference to the career than personal life and is she compatiable for all these things? You should also look into this particular aspect, before alleging her and her parents for your problems and take them to task.
4. I do not take your wife's allegation of unnatural s*x very seriously. I suppose in her mind it was planted by her legal adviser to bring you back. But, if....if.... really, your wife wants to bring such charges against you and it is of her own allegation and not of proding from any legal counsel, even though you cannot be imprisoned by having a prudent advocate on your side, you must start to take steps to take divorce from her. The reason is a black mailing wife (if you are really innocent of such offence) cannot be cohabitated, because times go by, new black mailing threats emerge with cyclonic furocity.
Again, the real solution for your problems life once you start to think stepping into her shoes.