Give it a try. If it stutters at times the following might apply:

If possible, get more RAM. 2 GB is enough for MIDI but not for RealTracks if there are more than one chord change per every four beats. I did have that experience. Maybe you still get RAM on ebay for your machine decently priced. Often computers with the same age as yours don't accept more RAM --> get a new computer; one that has the option of having at least 16 GB RAM.

Your processor should still be fast enough, but more cores are better.

Running BIAB from an external disk using USB 2.0 also could slow down the data transfer for RealTracks. If you run it from a second disk, use an internal one. Newer SSDs could help, but: If you spend 400 bucks or more for an SSD with 1 marketing-TB, use that money more wisely on a newer machine.

Probably BIAB 2015 will run, since it is not yet a 64-bit software. But some of its properties and side tools and utility files may be a little more ressource consuming than your computer will welcomingly accept. It probably will be kind-a grumpy.

Desktop; i7-2600k, 8 GB mem., Win 10 Pro, BIAB 2017; RB 2017 - latest build
Laptop: i5-2410M, 4 GB mem, Win 10 Pro, BIAB 2017; RB 2017 - latest build