This isn't an income tax form. Well it is, but it is not THE income tax form. This is the IRS description of this form:
"Because tax-exempt organizations generally operate for charitable or other beneficial purposes, most income that they receive is exempt from tax under the Internal Revenue Code. Tax-exempt organizations are permitted to engage in income-producing activities that are considered to be unrelated to their exempt purposes. However, income from these activities may be taxable. This study measures income, deductions, and tax imposed on tax-exempt corporate and trust entities' unrelated business income. Data are compiled from Form 990-T, Exempt Organization Business Income Tax Return."
In this case its for some kind of Limited Partnership of which the WTBS has an interest. I can't find out much about "Provictor Property Fund" I think it is probably a Real Estate Investment Trust. The 400 million dollars is probably the total value of the trust, of which the WTBS owns some percentage. I suspect that there are lots of these forms floating around somewhere. The Watchtower is smart enough to be doing something with its money.