Islam, Christianity are outside our purview because they are alien-semitic religions, and are not regarded as 100% native to India. Besides, they do not belong to the period of the happening of Ramayana/Mahabharata, or to the evolution of these two epics through Centuries particularly upto invasion by Ghazni MOhammed (1000 CE). Sikhism is out of the scope of Ramayana study because it evolved during Moghul period.
In our earlier analyses and posts , we have examined many places in Madhya Pradesh, Chattisgadh, West Orissa, Jhar Khand (South of Ganga River), as probable locations of Ravana's Lanka, and Sugriva's Kishkindha, Matanga Hill and Sabari's Pampa Sarovaram.
The trigger for our arriving at about a 70% conclusion that Hanuman did not nearly hopped over the Bay of Bengal or the Indian Ocean or Pak Straits and that Rama did not cross Godavari, Krishnaveni and Kaveri Rivers-- we may recapitulate for the benefit of those who have not read the earlier post is:
When Hanuman, Angada, Jambavan et al South-bound team were lifted from the nether-world underground cave of Svayamprabha who gave them food, water, honey etc., clarified to them that she was not Sita, and advised them to go to Lanka.
PART 4, CHAPTER 52, VERSEs31 and 32, SANSKRIT:
Esha vinhdhyO girihi shrImAn naanaa druma latA Ayutaha
Esha prasravaNaha shailaha sAgaro ayam mahA udadhihi
svasti vo astu gamishyaami bhavanam vAnararshabhAha
iti uktvaa tat bilam shriimat pravivEsha Svayamprabhaa.
Approx. Engl. gist: Here are Vindhya Hills, rich in numerous plants and creepers. These are the PrasravaNa Mountains. Here is the great Ocean. O the best among the ForestMen ! Let auspicious things happen to you. I shall enter my home. Then Svayamprabha entered her underground cave.
ybrao a donkey's observationsWhile writing that particular blog post, we observed that if Sea is to be adjacent to Vindhya Hills, the vAnaras were left by Svayamprabha near Mahendra Giri, which may be near Sompeta -Koraput - Barhampuram on the AOB (Andhra Orissa Border).
PrasravaNa Hills seem to be PApi konDalu on the banks of Godavari River between Bhadrachalam and Rajahmundry (Polavaram Project, Pattisam Project fame).
We also felt that Sugriva's Kishkindha could not be Pampa Sarovar near Hampi. Reason: This is possible only if Hanuman went upwards to the North instead of down to the South. Sugriva advised them to search in South. He had also given very very detailed guidelines about the places they will see during their south-ward search. If all the places mentioned by Sugriva are to be in Hanuman-Angada team's path, Kishkindha should be on the National Highway area between Allahabad and SasAram (Late Jagjivan Ram's Constituency). We also estimated it to be Mirzapur, South-eastern Uttar Pradesh. We also considered that South East to Mirzapur, in Jharkhand, there was Anjanadevi's Birth place, and automatically Hanuman's birth place.
Since writing those things, I spent nearly five years of sleepless nights with my brain, heart and mind gyrating and meandering on various places. For Ravana's Lanka, keeping in mind the Great Historian Late Sankalia's view (as far as I could recollect) who estimated that Ravana's Lanka was in Chota Nagpur Region on Jharkhand-West Bengal border. I zeroed down on Lanka as a Ganga River Island north of Bhagalpur, keeping in mind Trikuta hill, and another hill, apart from Rajagriha. We have also examined Bydyanath story of Ravana carrying the Atma Linga of Lord Shiva. They are all proximate to Bhagalpur.
We have also examined some islands on West-Mahanadi River, which have potential to be Ravana's Lanka.
Now, I have come across the Sirpur - Sabaripur town, Mahasamund Dt., Chattisgadh, near West Orissa / Chattisgadh border which has the potential to be Shabari's hermitage. Here is a link to this place in Chattisgadh, at Wikipedia:
Click to go to https://en.wikipedia.org/wiki/Sirpur_%28Chhattisgarh%29'
One quote from Wikipedia is very important:
"...The 7th century Laxman Temple (dedicated to lord Vishnu) is considered as one of the finest brick temples of India with a stone doorframe. First discovered in 1872 by Lord Cunningham,  the temple is famous for its interesting carvings. Recent excavations have uncovered 12 Buddh Viharas, 1 Jain Vihara, monolithic statues of Buddha and Mahavira, 22 Shiv temples and 5 Vishnu temples, an Ayurveda treatment centre, underground granary market and a sixth century ‘Ayurvedic snaan kund’ (ancient spa). ..."
The existence of 12 Buddha VihAras, 1 Jain Vihara, monolithic statues of Buddha and Mahavira, 22 Shiva temples and 5 Vishnu temples-- these are all important.
It is generally believed that Valmiki Ramayana and Vyasa Mahabharata evolved during the Gupta period.
Gupta emperors are regarded as great supporters of Hinduism, and to some extent Buddhism. But how about Jainism? After Maurya Chandra Gupta (grand father of Ashoka and founder of the Maurya Empire), who was reputed to have migrated to South India Karnataka's Shravana Belagola, which other Maurya- Gupta kings encouraged Jainism? Between the Mauryas and the Guptas, South Kosala was ruled by Pushya Mitra Sringa, Brihadridha et al, and they were also supporters of Brahminist Hinduism. (to continue. सशेष. సశేషం.)