Hi,
That dosn't tell me the current.
So assume the RED LED's are 2Vdp/LED, as you are using a 12V supply, this gives 5 LED * 2v =10Vdp per chain.
If you have one chain with a LED current of 15mA, this means you have to drop 2V at 0.015.
So you require a 133R resistor [ 120R] per chain.
So the current per chain with a 120R would be 2V/120R = 17mA
Using a 2N3904 transistor you could have 6 chains, in parallel giving a total collector current of 100mA.
Do you follow.?