I need gcc 4.9.3 installed on my armhf debian box. But the version in the jessie repositories are 4.9.2 and the version in stretch is 5.
How can i get a particular version through the repositories?
Stretch currently has version 4.9.3, but that's about to be replaced by 4.9.4. You can get the last set of packages for 4.9.3 reliably from Debian snapshots, including for
armhf. The corresponding repository is
deb http://snapshot.debian.org/archive/debian/20160415T115342Z/ sid main
(see the instructions given on the main snapshots page for details of how to use this).