Paul wants to stress that the “utter dependability of our hope” (Rom 5:5a) is based not on the power of human love (v 7) but on God’s love as demonstrated by his death for sinners (vv 6, 8).
In v 6 Paul writes, “For while we were still helpless, at the right time Christ died for the ungodly” (Ἔτι γὰρ Χριστὸς ὄντων ἡμῶν ἀσθενῶν ἔτι κατὰ καιρὸν ὑπὲρ ἀσεβῶν ἀπέθανεν). There are a couple of interesting points to be made about the Greek.
First, γάρ is introducing not just v 6 but vv 6-8 (see Moo). If we used the simplistic gloss “for,” as do most translations, it makes the connection between paragraphs a little harder to parse. How does Christ’s death for sinners relate to our hope stemming from our justification? But when you see the γάρ introducing all three verses, it makes the flow of thought a little clearer.
This explains the NIV’s unusual “You see.” The phrase does a great job of setting you up to see the entire paragraph as related to the preceding. “You see, at just the right time, when we were still powerless, Christ died for the ungodly.”
The other point is the redundant double use of ἔτι. Most likely, both modify the genitive absolute, ὄντων ἡμῶν ἀσθενῶν. The first is moved forward for emphasis — it was when we were still sinners that Christ died. The second adds repeated emphasis. Try to say that in English!
This may be what the NLT is trying to do. They ignore the initial γάρ, probably viewing it as a paragraph marker, but both occurrences of ἔτι can be felt in, “When we were utterly helpless, Christ came at just the right time and died for us sinners.” There is no Greek word corresponding to “utterly,” as I assume it comes from the two occurrences of ἔτι.
This verse also exposes the myth of word-for-word translation. None of the other translations, including NASB, ESV, HCSB, represent both occurrences of ἔτι.