First of all as Kapil already said never use Turbo C.
Now the reason you're getting this answer is as follows:
I think your Turbo C++ is 16 bit version.
Thus the max range you can have of int type is $-2^{15}(32767) \;to\; 2^{15}-1 (-32768).$
Thus your integer rounds to $0$ again after $2^{16}=65536$.
Binary representation of $5565654$ is $10101001110110011010110$. But since the compiler is 16 bit only thus the no. which gets stored is $1110110011010110$ (last 16 bits).
$1110110011010110=(60630)_{10}$.
Since the MSB is $1$, this is a negative integer. Take it's 2's complement of $1110110011010110$and you get $-4906$