Step 1: Check in which module do you want to add your menu module list is in ohrm_module table.
Step 2: Check under what user roll you want to add menu user roll is in ohrm_user_role.
Step 3: Add Screen on bases of module (step 1) insert data into ohrm_screen
step 4: Add Menu Item on bases of Screen (step 3) insert into ohrm_menu_item
Step 5: Assign screen to user on bases of user roll (step 2) and screen (step 3) insert into ohrm_user_role_screen
Step 6: Logout and login again. New menu will be there.
That's all