hi guys iam new to gyros and have little confusion in gyro setup
i have a aelous 50 3d heli n iam confused to 'where should i place it on my heli
i have a images below so any one know abt this plz help me

Put it as far as you can from the engine.

Both places have pros and cons, so I plant it where ever I see the tail behaving perfectly for me.

oh kk but how to connect gyro ?
i have seen in manual and connected them but rudder servo is not responding
what should i do ,i should change any setting in my transmiter?

First: The gyro and the servo connector have 3 wires one for sense another positive and the other one negative. make sure you match them properly for connection. you manual might tell you what is what.

Second: Check the mode on the Gyro. If its digital or analog mode. Gyro must be set to digital if the servo is digital else keep it to analog (set digital off). Again check the manual for the info.

hey, why is your muffler pointing up north

i suggest you first sort out the muffler orientation and then come to the electronics. your engine seems to be mounted facing the wrong way. check if the clutch face upwards to the rotor head assembly. if it is then your muffler should be parallel to the landing skids.

your model for ref :

ok examined your photos closely, you are using a aero muffler . you need to use a heli muffler on a heli engine.
what engine are you using there ?

my engine was asp s46h

ok thats a heli engine but get your self a heli muffler aswell. aero mufflers dont do for a heli. heli engines work in a different rpm range to their aero counterparts and therefore have a greater exhaust/pressure requirement.