Indexing depends on links pointing to the site, not the age of the name of it. Of course if the site already exist, it's goona be easier to get added pages indexed, but for a site that was not existing yesturday, it's gonna be the links pointing to it that will determine the speed at which it will be indexed.
indexing has nothing to do with age of domain as already said its off page factor which depends on the links pointing to ur site how easily ur site is found by se crawlers.. u can create google sitemaps to make crawling easier.