I will be reaching by plane to Gay . what is the best way to cover all these places and babadham darshan and go back to varanasi
It depends how many days you have for this trip.
Lets make it easy..
Once you reach Gaya, take a taxi or auto to reach Bodhgaya
See Bodhgaya either by taxi or by walk as most of temples and monastries are within 1-1.5kms of areas.
Then book a cab from trusted agent and cover Rajgir, Nalada and Pawapuri. If you can give 2 days for Rajgir and see its beauty.
Next if you want to return Gaya and catch train or Bakhtiyarpur near by but if you have late night train avoid Bakhtiyarpur.
From either of train station you can reach Jasidih ( Closed to Babadham).
Have good trip
Please also research and check flood situation before coming as Aug-Sep its rainy season and can expect much rains
From Rajauli, is it Nawada-Hisua-Rajgir OR Sirdala-Daulatpur-Hisua ? I read somewhere that Rajauli-Nawada route of 30 kms takes 90 mins to cover.
The problem between Rajauli Nawada Bihar sharif road is traffic jam,The highway is still two lane and traffic is heavu,you can take Rajauli Hisua road.Now a day in Bihar no one know where we can get stuck in jam and have to wait for hours.If you go via Nawada then can visit Pawapuri temple on the way and return and also Nalanda if move little further and return via Bodhgaya.Edited: 18 April 2018, 15:08
If one is looking to go to Rajgir Ropeway from Ranchi, it's advisable to take Ranchi-Barhi-Dobhi-Bodh Gaya route onto Patna-Gaya-Dobhi route to NH120. Take a left turn to Bhindus-Chamandih Road, crossing Gehlaur as shown on Google maps, if you put destination as Rajgir Ropeway. It's a good stretch of road passing through villages & some beautiful rock mountains when nearing Rajgir (reminded me a little bit of Utah in USA). But it's better to take this stretch during daylight, as visibility may not be good in the night & it may be isolated.
You'll avoid the traffic a lot through this stretch though.
Nawanda NH-31 is being repaired and seems better now