I'm going to guess that you're from India. I'm Canadian and working in the US. We have tax treaties around 401(k)s and sort of around Roth IRAs, so I've been contributing and will likely leave them here until full retirement age if I go back to Canada. I don't know anything about India's tax treaties with the US though so that's a different story.
If you don't have tax treaties making the gains not taxable until you withdraw the money AND you're pretty confident you'll move back, I wouldn't be contributing a single penny to your 401(k) beyond the employer match, which in your case is zero. I probably wouldn't be contributing to the Traditional or Roth IRA either if I were you - you'll still have to pay early withdrawal penalties on that. Why? When you withdraw the entire balance early, it'll be subject to normal taxation PLUS a 10% early withdrawal penalty, so if you have a huge balance, you could end up paying more in taxes than you would have along the way.
I would open a Vanguard account and use the following index funds:
* Vanguard Total Stock Market Index Fund Investor/Admiral Shares
* Vanguard Total International Stock Market Index Fund Investor/Admiral Shares
* Vanguard's Intermediate-Term/Long-Term Tax-Exempt fund or the one for your state
(in whatever ratio you feel most comfortable with)
As an immigrant still on a work visa, I also keep a full 12-month emergency fund in cash. If I lose my job, I'm in a bit of a bind. I also won't go work for a startup until I get a green card.