hey guys i am a beginner and i am a car lover i just wanna know, how do brushless motors change their rotating directions in a rc car using tx
?

Not from the TX.  It is done usually by swapping any 2 of 3 wires that go from ESC to motor.  The direction can also be reversed in ESC settings on certain ESCs (especially car specific ones).

thanks anwar sir

then i just want to ask how do rc cars reverse back? or do they go only in one direction

Many car (and boat) ESCs specifically support reverse function.  This is not available in aircraft ESCs.

thanks a lot once again sir........

can any one plz tell me where to get cheap rc products in delhi??

u can get rc products in Delhi from mr. Anam (RC Hobby addict) , Mr. V.K.Singh (RC Electro) .

Ganeev, we used this ESC on our Hovercrafts to reverse the Thruster motors. They work well:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11743

Regards.

Are you asking this:

1. Related to RC cars reversing under control from TX - ie driving in reverse.
2. Changing direction - want to switch between going front and back related to TX input.
3. Related to plane brushless motors.

i m talking abt both 1&2 options...
i m more interested in cars than planes or helis!!!!!!!!!!!1