Right of way

I am living in Goa India, My house has two gates at the front and a gate at the rear side. According to the original plan the road behind our house is our official house access road, But when we constructed our house 30 years back the road in the front (main road) was suppose to be converted to National Highway and would consume a portion of the plot infront of our house (which has a building now – which was non existing then). This would render the plot infront unsuitable for any construction as its area would be reduced considerably. So that time we decided to construct our front side towards the main road. This plan was passed and we constructed our house. And we have been using the gate 1 (small gate in the centre of compound wall) for access to the house. Gate 2 (another gate for accessing vehicles) at was made recently about 7 years back for garage Few years later the National Highway was diverted to some other area and the plot infront now was suitable for construction. The building was constructed 6 years back about 5 meters away from our compound wall (5 meter gap is the PWD area running parallel between house and building that has underground pipeline running).The building under passage is located ahead of our gate1. There is an open space as marked of about 32 sqmt to the right side of the building which we use as access to our vehicles to enter gate 2 . Gate 2 was made in our compound wall 7 years back and there was no formal legal procedure followed. Whenever we enter our house on foot from the main road to the gate 1 through the under building passage , one of the residents (Mr. A) of the building threatens us not to use the path. (and says that is path is from the rear road – which is true, but our front side is towards main road). The residents of the building use the PWD area to park their vehicles and this blocks our gate 1. Also when I park my bike in the PWD area infront the house Mr. A threatens to damage my vehicle even if I use the way through the open space. Mr. A now plans to build a garden in the open space (32 sqmt), so as to render us unable to use the front side for access. He has approached the owner of open space to give his consent to the municipality to have a small garden in the open space, which the area owner still has not given. Please guide me 1. Whether I have the right to access the route which runs below the building to enter house through gate 1(or is this trespassing)? 2. Can the open space be used for developing garden or any such thing or I have the right to use it (keeping in mind that the gate 2 is not officially in the house plan)? 3. How can I LEGALLY ensure that my way to enter the house from the front is not disturbed? I don’t know how to attach a rough sketch in support and for clarity. But I really need some genuine legal guidance. Please help me.