Retirement plan contribution limits

Let's say my:

Before Tax Income for the year: $10,000

Amount withheld and subsequently paid in income taxes: $2,000 ($1,500 Federal + $500 State)

Employee contribution to Roth 401K plan at work: $7,000

 

My question is: How much can I contribute to my Roth IRA that year?

$1,000? (After Tax Income - Contributions to other plans)

$3,000? (Total Income - Contributions to other plans)

$6,000? (Total Income up to $6,000/year limit regardless of my contributions to other plans)