data_forward_spot <- read.csv("forward_rates_USD_vs_INR_spot_1m_3m_6m_12m.csv")
data_forward_spot$date <- dmy(data_forward_spot$date)
This is the code.
plot(data_forward_spot$date, data_forward_spot$forward_1m, type = "l",col = "red",ylim = c(-0.5,3.0),
xlab = "Year", ylab = "Forward rate (INR)", lwd= 2,main = "Forward rates for 1M, 3M, and 6M")
lines(data_forward_spot$date, data_forward_spot$forward_3m, type = "l",col = "blue", lwd= 2)
lines(data_forward_spot$date, data_forward_spot$forward_6m, type = "l",col = "green", lwd= 2)
legend("bottomright", legend=c("1-Month", "3-Months","6-Months"),
col=c("red", "blue","green"), lty = 1:2, cex=0.7)