(Problem Solved) Hash(m1 xor m2) = Hash(m1) xor Hash (m2) Is this true in case of SHA1?

No this isn't true. (And it would only take a few seconds to actually test it yourself.).

No, it is not true. A function would have to go out of its way to have this property. SHA1 incorporates bytes from its stream on block at a time starting with a predefined initial value.

At the end it incorporates the length of the byte stream into the byte stream and pads out to the block size.