Suggest that you have a word with one gentleman Mr.Srinivasa Murthy - who takes care of accomodation - in Ramanasramam (RAmansramam phone no+91- 4175- 237200)or any other staff member in Sri Ramanasramam who can guide you ,since Sri RAmanasramam has a lot of foreign visitors .
Suggest that you keep the addresses and phone numbers of your country's embassy/consulate office handy.
Keep your money in 2 or 3 places and be weary of unscrupulous auto rickshaws.At the Tiruvannamalai temple ,there will be people asking for money to feed cows or something like that - stay clear from all of them ,be fearless, your money is yours to be spent at your discretion and you are a guest of India. Be familiar with the conveyance fare, whether you are travelling in an auto or a call taxi don't pay more and feel short changed . If there is a facility in your ashram, to deposit your belongings safely ,please use that while still keeping some money for daily use.Try to have 2 or 3 Indian confidantes whom you can rely on in case of any difficulty .
You probably will be coming from Chennai (5 hour journey to Tiruvannamalai ) in which case there are cabs available. You can check with Sri Ramanasramam and see if you can club your journey with someone else both while going and while returning .
If you a lady, then needless to say additional care has to be taken .
The southern part of India is a safe place for women to travel but all the same try to go everywhere with some trustworthy company of both sexes.
While going on Girivallam please see that you have company on above lines .Tiruvannamalai like the rest of South India is facing severe water shortage and you should be aware of this, while not being perturbed.
In case of any difficulty, you can even write on this forum , bid your time and there will be surely someone who will be in a position to help you to get out of that difficulty .There may some forum member at Tiruvannamalai or there may be someone nearby from Chennai or Bangalore who can help.
Having said all this ,which are of the nature of elaborate precautions since you are visiting a foreign country (hope for the best but be prepared),place your faith in Bhagavan.While taking above precautions and other precautions suggested by others, still be free and be peaceful and trust Bhagavan to take care of you .He never fails us.