Welcome to Numista SIPE. Of course the Roman coins and the Indian coin are very difficult but Numista has wonderful tools to help you with the identification of your other coins and making the identification yourself is much more satisfying and fun, isn't it?
For your first coin, you can easily read PIEZAS and CINCO (and even a few more), so type these words in the "Search" box (top right of every page), no need to type the words in capitals and here's the result:
https://en.numista.com/catalogue/index.php?r=cinco%20piezas&ct=coin
The more words you can decipher the higher the chance you can narrow down the hits. In this particular case those two words are already enough to narrow down the hits to only 2 coins, amongst them yours of course.
On the fourth coin you can read ALFONSO and 1877, so put these in the "Search" box and you get:
https://en.numista.com/catalogue/index.php?r=1877%20alfonso&ct=coin
Only 5 hits. Yours is the first or the second. Like
Giobruno said, the denomination isn't visible anymore so you have to weigh your coin or measure the diameter to know which one of the two is yours. Attention: words must be complete. Suppose you can only read ALFONS in stead of ALFONSO, the search tool won't find your coin. You can try to solve this by typing a * for the letters you can't read, for instance alf*n**:
https://en.numista.com/catalogue/index.php?r=1877+alf*n**&ct=coin&tb=y&tc=y&tn=y&tp=y&tt=y&cat=y&ru=&ca=3&no=&v=&d=&i=&a=&dg=&m=&f=&t=&w=&u=&g=&se=&c=&wi=&sw=
This works but apparently not if one of the first three letters are replaced by an asterisk. If you replace the first letter you get 0 results, if you replace the second letter, your coin will still be in the results but together with 415 others which is of course a lot.
On your sixth coin you can read 1 and 1982. You can put those in the search but you'll see you'll get a lot of hits, too many (654):
https://en.numista.com/catalogue/index.php?r=1+1982&ct=coin&tb=y&tc=y&tn=y&tp=y&tt=y&cat=y&ru=&ca=3&no=&v=&d=&i=&a=&dg=&m=&f=&t=&w=&u=&g=&se=&c=&wi=&sw=
To narrow down the hits, instead of putting these numbers in the "Search" box, click on "Coins" (under the "Search" box at left) and then click on "+ Add filters". Then type 1982 in the "Year" box and 1 in the "Face value" box.:
https://en.numista.com/catalogue/index.php?r=&ct=coin&tb=y&tc=y&tn=y&tp=y&tt=y&cat=y&ru=&ca=3&no=&v=1&d=&i=&a=1982&dg=&m=&f=&t=&w=&u=&g=&se=&c=&wi=&sw=
The hits are narrowed down to 265, which is still a lot. But you see, there is also a ship on your coin. So go back to the tab with the search result and click on "Edit filters". Then type in the "Tag" box "ship" and while typing you'll automatically get the result "Boat and ship" (you have to click on that). If you already had closed that tab, you'll need to click again on "Coins" and "+ Add filters" and type 1, 1982 and Boat and ship in the correct boxes. Now the hits are narrowed down to 19 which is acceptable:
https://en.numista.com/catalogue/index.php?r=&ct=coin&tb=y&tc=y&tn=y&tp=y&tt=y&cat=y&ru=&ca=3&no=&v=1&d=&i=&a=1982&dg=&m=&f=&t=&w=&u=&g=&k%5B%5D=20&se=&c=&wi=&sw=
Attention: this will only work if the coin you're searching is already tagged. This feature is rather new so not all the coins are already properly tagged.
And now your last coin. You can see 100 and 49 on your coin so you can type it in the "Search" box but then you get 65 hits. So better use the filter again and put 100 (which is obviously the denomination) in the "Face value" box. 47 might look like a strange number but if you know anything about regnal years, you'll know you have to type that in the "Year" box, and the result is only 1 hit, your coin:
https://en.numista.com/catalogue/index.php?r=&ct=coin&tb=y&tc=y&tn=y&tp=y&tt=y&cat=y&ru=&ca=3&no=&v=100&d=&i=&a=49&dg=&m=&f=&t=&w=&u=&g=&se=&c=&wi=&sw=
Maybe you never heard about a regnal year (it's the amount of years a new ruler is in charge), but if you find 2 different numbers on a coin, the first one will be the denomination, and the second one almost always will be the date, even when it looks a strange number like 49.
I will see if I can add more details for the other coins soon.