Secure investment for 3 to 4 years

I want to invest 7.5 million in real estate islamabad for 3 to 4 years. Please suggest me where to invest for maximum value appreciation. I have some options below
1) bahria enclave j block
2) dha phase 3 and 5
3)top city or mumtaz city
4)b-17
5)bahria phase 8

Please guide me where to invest?