How long for a page is starting to rank in Google, i am using XML site index as well, en the pages are SEO optimized
To rank your site page will depend on how competitive your site is for the targeted keyword phrases. Usually low competitive keyword took 1 month or 2 months to rank while high competitive keyword will take 6 months onwards to rank, therefore, it also depends on skills, knowledge, and experience of the optimizer.
It can take from a few weeks to SEVERAL months. But you need good and unique content and STRONG backlinks in order to achieve good ranking!