Thanks for replying Tom.

According to my study in I2C protocol after 8th clock pulse Master leaves the SDA line and Slave needs to pull that to LOW if slave Address matches for ACK and for NACK the left SDA line stays high.

As per our observation in Logic Analyzer:

slave address of OV5640 camera is 0X78 for Write
enter image description here-

We are able to receive 0 as ACK bit from slave but according to SCCB Datasheet enter image description here-Datasheet snapshot
there can be possible of sending 0 and 1 or Don't care (x) contradict for ACK bit.

So we are not able to consider as proper ACK from slave side.

If anyone has proof for Slave will send only 0 for ACK and not send don't care at 9th clock pulse is most preferable for us.