If you are referring to any one of his forms, the first perfect Rasengan Naruto made without the use of clones was when he fought Sasuke at age 12 using his one-tailed Version One state instead. He didn't make regular use out of the Rasengan without clones though until he achieved the Nine-Tails' Chakra Mode. At this point he used chakra arms instead of clones. His first use without chakra arms was during his battle with Tobi after he unlocked his Kurama Mode. He then showed the ability to use it simply in his Sage Mode. Both of these latter two were also at 16. However, the first perfect Rasengan he made without any chakra arms, forms, or clones, was done during his fight with Sasuke, just after he turned 17.