you should not buy any commercial property to save capital gains tax. No exemption is available.
You can buy residential plot to avail exemption u/s 54F. There are few conditions:
1. You have to construct new house on this plot within 3 years from sale of old property.
2. You have to invest the TOTAL SALE CONSIDERATION and not long term capital gain in new house. For this you have to keep the remaining sale money after investing in plot in capital gains account with a bank. You can withdraw from this account only for payments in relation to construction of new house.
3. You should not have more than one residential house as on date of invstement in plot.
4. You should not acquire any other house (except the above construction) during next three years.
Sounds difficult. My advice is that you invest the LTCG in capital cains bond issued by NHAI or REC.