mercury cougar 2001. Transmission stopped working

Nice car, ots of new parts installed recently like shocks, rakes, ll engine parts etc. unfortunately transmission broke as it does not shift gear in, o selling as is with bad transmission. New engine was replaced 6 months ago with 100K miles on it. New shocks, rakes, tc.. Bought this car with broken engine and fixed it all for myself but half year later car stopped shifting gears, ook to mechanic he said it may betransmissionor computer. Bought other car so have this one for sale. On odometer there is 175.000 miles.Selling only for cash on pickup.