is it possible to hook my 1060 in lower PCIe lanes. Will there be any performance difference or should i have to stick with the top one.
Possible -yes. Performance difference - also yes.
For single GPU it's recommended to use upper PCIE x16_1 slot.
Lower PCIE x16 slots will operate at lower performance modes. When using PCIE x16_2 slot, slot configuration will switch to x8/x4 mode. PCIE x16_3 slot operates at x4 mode max.
Read motherboard manual.https://www.asus.com/Motherboards/ROG-STRIX-B350-F-GAMING/HelpDesk_Manual/