Once you marry, let's say in India, petition her for a CR-1 visa by filing the I-130 petition. Once approved, the petition goes to NVC, which forwards the file to the Embassy in India for an interview. The process takes about 12-14 months, she gets a green card upon US entry, and that's the quickest way for a spouse to migrate.
Per my experience on this and other forums, USCs with an Indian national spouse/fiance seem primarily interested in getting the person into the US as fast as possible. Both of OP's posts are directed that way. But India being a largely conservative society, most families do not let a daughter leave home without being married. And while threads on various forums do not constitute a trend, I reckon roughly half the India K1s are denied due to one factor or another. CR1 is a surer (and overall more cost effective) bet towards a green card.