In case anyone else is traveling in June 2016 (like me) tickets for the TGV -> Basel are already on sale for the 10:23 departure. Don't know why that particular train is already available, but if that's your route and date and time then you can save some money buy purchasing the limited cheapest non-flexible ticket.
That's weird because I've been waiting and waiting to buy Paris to Barcelona TGV tickets for April 9th and they were supposed to come online for sale on Saturday and when I went to buy them, poof!...they were gone and now they're not for sale until January. I've tried TGV, loco2 and capitainetrain for purchases and struck out everywhere. Where did you buy your tickets?
It's just that particular date and time that's available for some unknown reason. You can buy direct at www.sncf.com if you can get your card to work. Also available from resellers like captaintrain.com or raileurope.com. I actually purchased mine from SBB Group Travel because I'm taking a group from Paris -> Basel -> Interlaken.
SNCF doesn't have them either...even if I avoid the auto-redirect to RailEurope by pretending I'm picking up my tickets in France. Oddly, though, RailEurope is selling them up through April 2nd, but they're tacking on about $25 per ticket. I'm sure I'll track down my tickets, but, like you, I want those first release limited tix at the really good prices.
I believe it was about a month ago that SNCF released a range of tickets for sale for travel into summer, but certainly not all routes. Others may be offered within the more standard range of 3-4 months ahead, but SNCF doesn't really have to follow any rule. Probably a good idea to sign up for SNCF's email newsletter so you'll receive alerts from them.