query regarding mpu6050 module

Projects General Guidance
1

can i use GY-521(mpu6050) for other than arduino based applications like for AVR applications.
i.e., can i use it for interfacing to atmega16 directly?

2

can i use GY-521(mpu6050) for other than arduino based applications

Of course. the MPU6050 doesn't care where the data goes.

can i use it for interfacing to atmega16 directly?

Only you can answer that.

3

Does the atmega16 have I2C?

4

Atmega16 has TWI, the Atmel name for I2C.