I own a LP in my IRA and I have K-1 Schedule, I do not find a place to enter. Where to enter I2 asking if this partner is in a retirement plan?

Since the IRA has the K-1 income, the K-1 form reporting the income does not need to be reported on your return. Once you start taking distributions from the IRA, then the distribution information will need to be reported. 

Regarding the I2 box on the K-1, within TuboTax, after selecting to enter a partnership K-1, a question is asked whether the K-1 is for an IRA or retirement plan and asks the user to mark the box on the screen if the I2 box is marked.  Once marked on the screen, a new message gets displayed letting you know that the K-1 income does not need to be reported on your return.  See sample screenshot below.