Assuming you have a Soviet Tokarev pistol in issued form, and not one of the many variants from other nations, or altered in some way, sounds like it's a 1938 or later TT-33.
You're likely going to be surprised when you get it in hand, because the two-letter prefix in English probably won't match what's stamped in Cyrillic. First, I haven't seen an E-form (Ye or the rather different looking E) on CCCP serials (but it could be). But is the N actually a backwards-N (which is I), or an H (which is a proper N); see what I mean?
Your full serial will be the year, factory mark, and number with prefix. Like 1944 triangle (Izhevsk) RB1234, or 1937 star (Tula) 2345. So it will have a good amount of information already.
They were all made in Tula to start. The letter prefix was instituted in 1938, to conceal actual production totals; theoretically the two letters could mean batch X of month Y, but without access to secret factory records we can't decode. Tula was abandoned in the face of the Nazi advance very late in 1941, and Izhevsk picked up production, until ceasing in '53.
There are a few possible minor feature differences, depending on if yours turns out to be pre-War, wartime, post-War, and whether it was up-graded in refurbishing.
