If I made 33876.00 in service connected disability can I collect fot homestedd credit if I paid 6600.00 in rent for 2011 ?

I do not practice in Wisconsin, so I am NOT 100% sure of this, but, off-hand, I would say no, because service-connected disability is NOT taxable on the federal return and most states follow the federal lead in this.

If you received NO taxable income, the Homestead credit is mute, because (I believe) you must have taxable income to claim it.

A phone call to the Wisconsin tax department should get you a definite answer.