You haven't mentioned properly about Nifty 50 @ what price taken or how long are you holding? Question is incomplete? Are you talking about ETF or MF or Options trading?
Well, if you want to invest for a short duration, prefer SIP.For the Long term goal say more than 5 years, do Lumpsum.
@pranavj09 markets are always in volatile state. none knows when markets will correct. doing SIP in equity MFs is best option.