In the circuit attached has a transistor connected in parallel configuration.
can I use single base resistor for the 2 transistors(2N2222A)

 

Yes you can, but think about it for a minute: Why don't we see people doing that all the time?

Transistors will share base current, but without the base resistors to swamp out voltage differences between the transistors the degree of sharing is uncertain.

 

Welcome to AAC!

That technique is best used with matched transistors. If you use dual transistors (in the same package) they'll be more likely to be matched and will track better over temperature.

 

View attachment 141231
In the circuit attached has a transistor connected in parallel configuration.
can I use single base resistor for the 2 transistors(2N2222A)

The bigger question is, why parallel two 2N2222a instead of just using a single transistor that can handle the current?