Block size = 64 words = 26
So, Block offset = 6 bits
No. of Blocks in Cache = 32 = 25 = No. of Lines in cache
Main Memory size = 256 Blocks = 256 * 26 = 214 .
Set No = (No. of lines in the cache) / 8 [ Since 8-way set-associative]
= 25 / 8 = 22
So set no = 2 bits
Hence TAG = 14 - (6+2)
= 6 bits