How transaction manipulation handles in Blockchain?
For instance, A has some (i.e: $10) money and A is sending half($5) of it to B. but C manipulate that transaction before going to Blockchain and set $10 instead.


This is not possible, provided the original transaction is signed correctly. In a regular transaction, you sign the inputs and the outputs. If someone changes the input or output amount, the signature is invalid, and the transaction will not be mined.