Using third party library named "nsetools" for fetching stock data
You never use stocks, so I removed it. It would also help if your qty actually had the exact same keys as you need for nse.get_quote (namely lowercase names), so I did that as well.

In addition, you can convert your whole code into one generator, which you can then sum over:

from nsetools import Nse
nse = Nse()

def get_closing(stock):
    return nse.get_quote(stock)['closePrice']

stock_qty = {"ADANIPORTS": 20, 
             "HINDALCO": 20,
             "ONGC": 20,
             "SBIN": 20 }

stock_gen = (get_closing(stock) * qty for stock, qty in stock_qty.items())
current_value = sum(stock_gen)


If you already have stocks, you could just do:

stocks = {
    "ADANIPORTS" : 284.95,
    "HINDALCO"   : 152.30,
    "ONGC"       : 279.70,
    "SBIN"       : 259.70
}

#stock name and quantity of stocks     
qty = {
    "ADANIPORTS" : 20,
    "HINDALCO"   : 20,
    "ONGC"       : 20,
    "SBIN"       : 20
}
current_value = sum(val * qty[stock] for stock, val in stocks.items())