Indian Rupee and Dollar are two different currencies, You need to see Foreign Exchange Rate to convert 1,50,000 Rs/- to Dollar.

Currently $1 = 60.17 Rs/-

so $2492.73 = 1,50,000 Rs/- as per current rate.

In america; First 3 digits represents Hundred, Next 3 digits represents Thousand, Next 3 Represents Million, Next 3 Represent Billions

Likewise in India; First 3 digits represents Hundred, Next 2 digits represent Thousand, Next 2 digits represents Lakh , Next 2 digits represents Crore

so 1,50,000 RS/- is read as; one lakh fifty thousand Indian rupees, which is
same as $2492.73

No. It depends upon Indian Rupee value converted to US Dollar value. For Ex:
Today dollar value to Indian rupee is 1 dollar is 58.64. So 150000 Rs would be 2557.88 dollar. You can check it out in currency converter.com