yes although kinda have to know what relay you are using; latching voltage and current
do you know if its a 12V relay? can you include a photo of it? can you connect it to 6V, and if that fails then try 12V? if either works, can you then measure the current?
Guess you will need at least voltage gain: **broken link removed** and **broken link removed** give the main idea. But common-emitter inverts the signal [Ov in gives Vout], so you will need two in series