I have invested in sbi magnum tax gain in oct 07 for three years.Now i want to redeem it.Tell me the procedure?

i have invested in sbi magnum tax gain in oct 07 for three years.Now i want to redeem it.Tell me the procedure as my agent says that only a few units can be redeemed right now and i have to wait for another three years to redeem the entire units.pls suggest.